solidworks simulation 2017 black book
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SolidWorksSimulation2017BlackBook
MattWeber
CAD/CAM/CAEExpert
GauravVermaTechnicalEditor
PublishedbyCADCAMCAEWORKS,USA.Copyright©2016.Allrightsreserved.
Nopartofthispublicationmaybereproducedordistributedinanyformor
by any means, or stored in the database or retrieval system without the
prior permission of CADCADCAE WORKS. To get the permissions, contact at
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NOTICETOTHEREADER
Publisher does not warrant or guarantee any of the products described in
thetextorperformanyindependentanalysisinconnectionwithanyofthe
productinformationcontainedinthetext.Publisherdoesnotassume,and
expresslydisclaims,anyobligationtoobtainandincludeinformationother
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Thereaderisexpresslywarnedtoconsiderandadoptallsafetyprecautions
thatmightbeindicatedbytheactivitieshereinandtoavoidallpotential
hazards. By following the instructions contained herein, the reader
willinglyassumesallrisksinconnectionwithsuchinstructions.
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butnotlimitedto,thewarrantiesoffitnessforaparticularpurposeor
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DEDICATION
Toteachers,whomakeitpossibletodisseminateknowledge
toenlightentheyoungandcuriousminds
ofourfuturegenerations
Tostudents,whoarethefutureoftheworld
THANKS
Tomyfriendsandcolleagues
Tomyfamilyfortheirloveandsupport
TrainingandConsultantServicesAtCADCAMCAEWORKS,weprovideeffectiveandaffordableonetooneonline
training on various software packages in Computer Aided Design(CAD),
Computer Aided Manufacturing(CAM), Computer Aided Engineering (CAE), and
Computerprogramminglanguages(C/C++,Java,.NET,Android,Javascript,HTML
andsoon).Thetrainingisdeliveredthroughremoteaccesstoyoursystem
andvoicechatviaInternetatanytime,anyplace,andatrequiredpaceto
individuals, groups, students of colleges/universities, and CAD/CAM/CAE
trainingcenters.Themainfeaturesofthisprogramare:
TrainingasperyourneedHighly experienced Engineers and Technician conduct the classes on the
software applications used in the industries. The methodology adopted to
teach the software is totally practical based, so that the learner can
adapt to the design and development industries in almost no time. The
efforts are to make the training process cost effective and time saving
while you have the comfort of your time and place, thereby relieving you
fromthehasslesoftravelingtotrainingcentersorrearrangingyourtimetable.
SoftwarePackagesonwhichweprovidebasicandadvancedtrainingare:
CAD/CAM/CAE: CATIA, Creo Parametric, Creo Direct, SolidWorks, Autodesk
Inventor, Solid Edge, UG NX, AutoCAD, AutoCAD LT, EdgeCAM, MasterCAM,
SolidCAM, DelCAM, BOBCAM, UG NX Manufacturing, UG Mold Wizard, UG
ProgressiveDie, UG Die Design, SolidWorks Mold, Creo Manufacturing, Creo
Expert Machinist, NX Nastran, Hypermesh, SolidWorks Simulation, Autodesk
SimulationMechanical,CreoSimulate,Gambit,ANSYSandmanyothers.
ComputerProgrammingLanguages:C++,VB.NET,HTML,Android,Javascriptand
soon.
GameDesigning:Unity.
Civil Engineering: AutoCAD MEP, Revit Structure, Revit Architecture,
AutoCADMap3Dandsoon.
WealsoprovideconsultantservicesforDesignanddevelopmentontheabove
mentionedsoftwarepackages
Formoreinformationyoucanmailusat:
cadcamcaeworks@gmail.comorinfo@cadcamcaeworks.com
PrefaceSolidWorksSimulation2017isanextensiontoSolidWorkspackage.Easy-to-
use CAD-embedded analysis capabilities enable all designers and engineers
to simulate and analyze design performance. You can quickly and easily
employ advanced simulation techniques to optimize performance while you
design,tocutdownoncostlyprototypes,eliminatereworkanddelays,and
saveyoutimeanddevelopmentcosts.
TheSolidWorksSimulation2017BlackBook,iswrittentohelpprofessionalsaswell as learners in performing various tedious jobs of Finite Element
Analysis.Thebookfollowsastepbystepmethodology.Thisbookexplains
the background work running behind your simulation analysis screen. The
bookcoversalmostalltheinformationrequiredbyalearnertomasterthe
SolidWorksSimulation.ThebookstartswithbasicsofFEA,goesthroughall
the simulation tools and ends up with practical examples of analysis.
Chapters on manual FEA ensure the firm understanding of FEA concepts
throughSolidWorksSimulation.Thebookcontainsourspecialsectionsnamed
“Why?”.Wehavegivenreasonsforselectingeveryoptioninanalysisunder
the “Why?” sections. The book explains the Solver selection, iteration
methods like Newton-Raphson method and integration techniques used by
SolidWorks Simulation for functioning. A chapter on Model Preparation is
added in this edition to help you understand the procedures of preparing
modelforanalysis.Someofthesalientfeaturesofthisbookare:
In-DepthexplanationofconceptsEvery new topic of this book starts with the explanation of the basic
concepts.Inthisway,theuserbecomescapableofrelatingthethingswith
realworld.
TopicsCoveredEverychapterstartswithalistoftopicsbeingcoveredinthatchapter.
Inthisway,theusercaneasyfindthetopicofhis/herinteresteasily.
InstructionthroughillustrationThe instructions to perform any action are provided by maximum number of
illustrations so that the user can perform the actions discussed in the
book easily and effectively. There are about 600 illustrations that make
thelearningprocesseffective.
TutorialpointofviewThe book explains the concepts through the tutorial to make the
understandingofusersfirmandlonglasting.Eachchapterofthebookhas
tutorialsthatarerealworldprojects.
“Why?”Thebookexplainsthereasonsforselectingoptionsorsettingaparameters
intutorialsexplainedinthebook.
ProjectFreeprojectsandexercisesareprovidedtostudentsforpracticing.
ForFaculty
If you are a facultymember, then you can ask for video tutorials on any of the topic,exercise,tutorial,orconcept.
FormattingConventionsUsedintheTextAllthekeytermslikenameofbutton,tool,drop-downetc.arekeptbold.
FreeResourcesLink to the resources used in this book are provided to the users via
email. To get the resources, mail us at cadcamcaeworks@gmail.com or
info@cadcamcaeworks.com with your contact information. With your contact
record with us, you will be provided latest updates and informations
regardingvarioustechnologies.Theformattowriteuse-mailforresources
isasfollows:
SubjectofE-mailasApplicationforresourcesof____________BlackBook.
Youcangiveyourinformationbelowtogetupdatesonthebook.
Name:
Coursepursuing/Profession:
ContactAddress:
E-mailID:
ForAnyqueryorsuggestionIf you have any query or suggestion please let us know by mailing us on
cadcamcaeworks@gmail.com or info@cadcamcaeworks.com. Your valuable
constructive suggestions will be incorporated in our books and your name
willbeaddressedinspecialthanksareaofourbooks.
AboutAuthorTheauthorofthisbook,MattWeber,haswrittenmanybooksonCAD/CAM/CAE
books. He has written SolidWorks 2017 Black Book as a CAD companion forthis book. When SolidWorks Simulation 2017 Black Book covers details of
simulation, the SolidWorks 2017 Black Book covers all the tools and
techniquesofmodeling.Theauthorhashandonexperienceonalmostallthe
CAD/CAM/CAE packages. Besides that he is a good person in his real life,
helpingnatureforeveryone.Ifyouhaveanyquery/doubtinanyCAD/CAM/CAE
package, then you can directly contact the author by writing at
cadcamcaeworks@gmail.com
The technical editor of the book, Gaurav Verma, has written books on CAM
packages. One of his most selling book is Creo Manufacturing 2.0 for
Designer and Machinists. He has also written MasterCAM X7 for SolidWorks
BlackBookandAutoCADElectrical2017BlackBook.
SolidWorks2017BlackBookcanbeusedasSolidWorksCADcompanionwiththisbookforlearningaboutmodelingtools.
TableofContents
SolidWorksSimulation2017
BlackBook
TrainingandConsultantServices
Preface
AboutAuthor
Introductionto
Simulation
Chapter1
Simulation
TypesofAnalysesperformedin
SolidWorksSimulation
StaticAnalysis
DynamicAnalysis
Thermalanalysis
DropTestStudies
FatigueAnalysis
PressureVesselDesignStudy
DesignStudy
FEA
StartingSolidWorksSimulation
OnclickingSimulationAdvisor
OnclickingNewStudy
Basicof
Analyses
Chapter2
StartingAnalysis
ApplyingMaterial
AddingCustomMaterials
DefiningFixtures
FixturesAdvisor
FixedGeometry
Roller/Slider
FixedHinge
ElasticSupport
AdvancedFixtures
ExternalLoadAdvisor
ExternalLoadAdvisor
Force
Torque
Pressure
Gravity
CentrifugalForce
BearingLoad
RemoteLoads/Mass
DistributedMass
Temperature
FlowEffects/ThermalEffects
ConnectionsAdvisor
ConnectionsAdvisor
ContactSets
ComponentContact
ContactVisualizationPlot
Spring
Pin
Bolt
SpotWeld
EdgeWeld
Link
Bearing
RigidConnection
Meshing
RunningAnalysis
ResultsAdvisor
ResultsAdvisor
ModelOnly(NoResults)
NewPlot
ListStress,DisplacementandStrain
ResultForce
PreparingModel
forAnalysis
Chapter3
Introduction
ReferenceGeometry
Plane
PlaneParalleltoScreen
Axis
CoordinateSystem
Point
CenterofMass
Simplify
ExtrudedBoss/BaseTool
RevolvedBoss/BaseTool
ExtrudedCut
Mirror
SplitLinetool
MidSurface
SplitTool
CombineTool
AddingSolidBodies
SubtractingSolidBodies
IntersectTool
Move/CopyBodiesTool
ImportingPart
StaticAnalysis
Chapter4
Linearstaticanalysis
Assumptions
PerformingStaticAnalysis
StartingtheStaticAnalysis
ApplyingMaterial
ApplyingFixtures
ApplyingLoads
Meshingthemodel
RunningtheAnalysis
Results(FactorofSafety)
Optimizingproduct
ShellManager
PerformingStaticAnalysis
UsingStudyAdvisor
StartingtheStaticAnalysis
StaticAnalysisonAssembly
StartingAnalysis
ApplyingMaterialtoPartsofAssembly
SettingGlobalContacts
SettingContactManually
CreatingVirtualWall
CreatingFoundationBoltconnection
ApplyingLoad
Meshing
RunningAnalysis
AdaptiveMeshing
h-AdaptiveMeshing
p-AdaptiveMeshing
SubmodelingStudY
LoadcaseManager
Non-Linear
StaticAnalysis
Chapter5
NonLinearStaticAnalysis
TheoryBehindNon-LinearAnalysis
RoleofTimeinNon-LinearAnalysis
StartingNonlinearStaticAnalysis
ApplyingMaterial
ApplyingFixtures
ApplyingTimeVaryingForce
Runningtheanalysis
SettingPropertiesforNon-linear
StaticAnalysis
PerformingNonlinearStaticanalysis
onanassembly
StartingNon-LinearStaticAnalysis
ApplyingtheMaterial
ApplyingFixtures
ApplyingForces
ApplyingConnections
Runningtheanalysis
PerformingNonlinearStaticanalysison
aringunderapplicationofTorque
StartingNon-LinearStaticAnalysis
ApplyingtheMaterial
ApplyingFixtures
ApplyingForces
Runningtheanalysis
2DSimplification
StartingNon-LinearStaticAnalysiswith2DSimplification
ApplyBoundaryConditions
InterpretingResults
Non-Linear
DynamicAnalysis
Chapter6
NonLinearDynamicAnalysis
PreparingPartandStartingNonlinearDynamicAnalysis
ApplyingMaterial
ApplyingFixtures
ApplyingNoPenetrationContact
SettingInitialConditions
GlobalDamping
RayleighDamping
ApplyingForce
Runningtheanalysis
SettingParametersinNonlinear
DynamicAnalysis
Newton-RaphsonandModifiedN-RMethod
IntegrationMethod
FrequencyAnalysis
Chapter7
Introduction
StartingFrequencyAnalysis
ApplyingMaterial
ApplyingFixtures
ApplyingForces
SettingParametersfortheanalysis
Runningtheanalysis
LinearDynamicAnalysis
Chapter8
LinearDynamicAnalysis
Objectivesofadynamicanalysis
Damping
TypesofDynamicAnalysis
ModalTimeHistoryAnalysis
HarmonicAnalysis
RandomVibrationAnalysis
ResponseSpectrumAnalysis
StartingRandomVibrationAnalysis
ApplyingMaterial
ApplyingFixtures
ApplyingForceVibrations
ApplyingGlobalDamping
Runningtheanalysis
ModalTimeHistoryAnalysis
HarmonicAnalysis
ResponseSpectrumAnalysis
ThermalAnalysis
Chapter9
Introduction
ImportanttermsrelatedtoThermalAnalysis
ThermalLoads
Temperature
Convection
HeatPower
HeatFlux
Radiation
ContactSet
ThermalResistanceContact
BondedContact
InsulatedContact
PracticalonSteadyState
ThermalAnalysis
Startingtheanalysis
ApplyingMaterial
Applyingconvectiontothemodel
Applyingheatgeneratedbygascombustionon
theheadofthepiston
RunningtheAnalysis
Switchingfromsteadystateanalysisto
transientthermalanalysis
SpecifyingInitialTemperature
Runningtheanalysis
UsingProbetofindouttemperature
BucklingAnalysis
Chapter10
Introduction
UseofBucklingAnalysis
StartingtheBucklingAnalysis
SettingtheNumberofBucklingModes
ApplyingMaterial
ApplyingFixture
ApplyingtheForce
RunningtheAnalysis
FatigueAnalysis
Chapter11
Introduction
StagesofFailureDuetoFatigue
StartingFatigueAnalysis
InitiatingFatigueAnalysis
ApplyingorEditingS-Ndata
ModifyingtheStaticAnalysisearlierperformed
RunningtheFatigueAnalysis
ChangingPropertiesofFatigueAnalysis
RunningConstantAmplitudeEvents
onthemodel
Drop-Test
Chapter12
Introduction
StartingDropTest
ApplyingMaterial
CreatingMesh
ParametersforDrop
RunningtheAnalysis
PressureVesselDesign
Chapter13
Introduction
ThermalAnalysis1
StaticAnalysis1&2
StartingPressureVesselDesignStudy
SetupforDesignStudy
RunningtheDesignStudy
DesignStudy
StartingDesignStudy
SettingoptionsforDesignStudy
Specifyingparametersthataretobechanged
Specifyingrestrictionsforchanges
SettingGoalforthestudy
RunningtheStudy
FundamentalsofFEA
Chapter14
Introduction
GENERALDESCRIPTIONOFTHEMETHOD
ABRIEFEXPLANATIONOFFEAFOR
ASTRESSANALYSISPROBLEM
FINITEELEMENTMETHODV/SCLASSICALMETHODS
FEMVSFINITEDIFFERENCEMETHOD(FDM)
NEEDFORSTUDYINGFEM
WarningToFeaPackageUsers
GeometricDiscontinuities
DiscontinuityofLoads
DiscontinuityofBoundaryconditions
MaterialDiscontinuity
REFININGMESH
UseOfSymmetry
HIGHERORDERELEMENTSV/S
REFINEDMESH
OptimumprocessofFEAthrough
SolidWorksSimulation
ProjectonAnalysis
Chapter15
Project
StartingSimulation
PerformingtheStaticAnalysis
PerformingtheFrequencyAnalysis
PerformingFatigueStudy
PracticeQuestions
IntroductiontoSimulation
Chapter1
TopicsCovered
Themajortopicscoveredinthischapterare:
•Simulation.
•TypesofAnalysesperformedinSolidWorksSimulation.
•FEA
•UserInterfaceofSolidWorksSimulation.
SIMULATIONSimulation is the study of effects caused on an object due to real-world
loadingconditions.ComputerSimulationisatypeofsimulationwhichuses
CADmodelstorepresentrealobjectsanditappliesvariousloadconditions
onthemodeltostudythereal-worldeffects.SolidWorksSimulationisone
oftheComputerSimulationprogramsavailableinthemarket.InSolidWorks
Simulation, we apply loads on a constrained model under predefined
environmentalconditions and check the result(visually and/or in the form
oftabulardata).ThetypesofanalysesthatcanbeperformedinSolidWorks
aregivennext.
TYPESOFANALYSESPERFORMEDINSOLIDWORKSSIMULATION
SolidWorksSimulation performs almost all the analyses that are generally
performedinIndustries.Theseanalysesandtheirusearegivennext.
StaticAnalysisThis is the most common type of analysis we perform. In this analysis,
loadsareappliedtoabodyduetowhichthebodydeformsandtheeffects
oftheloadsaretransmittedthroughoutthebody.Toabsorbtheeffectof
loads,thebodygeneratesinternalforcesandreactionsatthesupportsto
balance the applied external loads. These internal forces and reactions
cause stress and strain in the body. Static analysis refers to the
calculation of displacements, strains, and stresses under the effect of
externalloads,basedonsomeassumptions.Theassumptionsareasfollows.
• All loads are applied slowly and gradually until they reach their full
magnitudes. After reaching their full magnitudes, load will remain
constant(i.e.loadwillnotvaryagainsttime).
• Linearity assumption: The relationship between loads and resulting
responsesislinear.Forexample,ifyoudoublethemagnitudeofloads,
theresponseofthemodel(displacements,strainsandstresses)willalso
double.Youcanmakelinearityassumptionif:
1. All materials in the model comply with Hooke’s Law that is stress is
directlyproportionaltostrain.
2. The induced displacements are small enough to ignore the change is
stiffnesscausedbyloading.
3.Boundaryconditionsdonotvaryduringtheapplicationofloads.Loads
mustbeconstantinmagnitude,directionanddistribution.Theyshouldnot
changewhilethemodelisdeforming.
Iftheaboveassumptionsarevalidforyouranalysis,thenyoucanperform
LinearStaticAnalysis.Forexample,acantileverbeamfixedatoneendand
forceappliedonotherend;refertoFigure-1.
Figure-1.Linearstaticanalysisexample
Iftheaboveassumptionsarenotvalid,thenyouneedtoperformtheNon-Linear Static analysis. For example, an object attached with a spring beingappliedunderforces;refertoFigure-2.
Figure-2.Non-linearstaticanalysisexample
DynamicAnalysisIn general, we have to perform dynamic analysis on a structure when the
load applied to it varies with time. The most common case of dynamic
analysis is the evaluation of responses of a building due to earthquake
acceleration at its base. Every structure has a tendency to vibrate at
certainfrequencies,callednaturalfrequencies.Eachnaturalfrequencyis
associatedwithacertainshape,calledmodeshapethatthemodeltendsto
assumewhenvibratingatthatfrequency.Whenastructureisexcitedbya
dynamic load that coincides with one of its natural frequencies, the
structure undergoes large displacements. This phenomenon is known as
‘resonance’. Damping prevents the response of the structures to resonant
loads. In reality, a continuous model has an infinite number of natural
frequencies.However,afiniteelementmodelhasafinitenumberofnatural
frequenciesthatisequaltothenumberofdegreesoffreedomconsideredin
themodel.Thefirstfewmodesofamodel(thosewiththelowestnatural
frequencies), are normally important. The natural frequencies and
corresponding mode shapes depend on the geometry of the structure, its
material properties, as well as its support conditions and static loads.
The computation of natural frequencies and mode shapes is known as modal
analysis. When building the geometry of a model, you usually create it
basedontheoriginal(undeformed)shapeofthemodel.Someloading,likea
structure’s self-weight, is always present and can cause considerable
changesin the structure’s original geometry. These geometric changes may
have, in some cases, significant impact on the structure’s modal
properties.Inmanycases,thiseffectcanbeignoredbecausetheinduced
deflectionsaresmall.
The following few topics – Random Vibration, Response Spectrum analysis,
Time History analysis, Transient vibration analysis and Vibration modal
analysisareextensionsofdynamicanalysis.
RandomVibrationEngineersusethistypeofanalysistofindouthowadeviceorstructure
respondstosteadyshakingofthekindyouwouldfeelridinginatruck,
railcar,rocket(whenthemotorison),andsoon.Also,thingsthatare
ridinginthevehicle,suchason-boardelectronicsorcargoofanykind,
may need Random Vibration Analysis. The vibration generated in vehicles
from the motors, road conditions, etc. is a combination of a great many
frequencies from a variety of sources and has a certain “random” nature.
Random Vibration Analysis is used by mechanical engineers who design
variouskindsoftransportationequipment.
ResponseSpectrumAnalysisEngineersusethistypeofanalysistofindouthowadeviceorstructure
responds to sudden forces or shocks. It is assumed that these shocks or
forcesoccuratboundarypoints,whicharenormallyfixed.Anexamplewould
beabuilding,damornuclearreactorwhenanearthquakestrikes.Duringan
earthquake, violent shaking occurs. This shaking transmits into the
structure or device at the points where they are attached to the ground
(boundarypoints).
Mechanical engineers who design components for nuclear power plants must
use response spectrum analysis as well. Such components might include
nuclear reactor parts, pumps, valves, piping, condensers, etc. When an
engineer uses response spectrum analysis, he is looking for the maximum
stressesor acceleration, velocity and displacements that occur after the
shock.Theseinturnleadtomaximumstresses.
TimeHistoryAnalysisThis analysis plots response (displacements, velocities, accelerations,
internal forces etc.) of the structure against time due to dynamic
excitationappliedonthestructure.
TransientVibrationAnalysisWhenyoustrikeaguitarstringoratuningfork,itgoesfromastateof
inactivityintoavibrationtomakeamusicaltone.Thistoneseemsloudest
atfirst,thengraduallydiesout.Conditionsarechangingfromthefirst
moment the note is struck. When an electric motor is started up, it
eventuallyreachesasteadystateofoperation.Buttogetthere,itstarts
from zero RPM and passes through an infinite number of speeds until it
attainstheoperatingspeed.Everytimeyourevthemotorinyourcar,you
are creating transient vibration. When things vibrate, internal stresses
are created by the vibration. These stresses can be devastating if
resonance occurs between a device producing vibration and a structure
respondingto.Abridgemayvibrateinthewindorwhencarsandtrucksgo
across it. Very complex vibration patterns can occur. Because things are
constantlychanging,engineersmustknowwhatthefrequenciesandstresses
are at all moments in time. Sometimes transient vibrations are extremely
violentandshort-lived.Imagineatorpedostrikingthesideofashipand
exploding, or a car slamming into a concrete abutment or dropping a
coffeepot on a hard floor. Such vibrations are called “shock, “ which is
justwhatyouwouldimagine.Inreallife,shockisrarelyagoodthingand
almost always unplanned. But shocks occur anyhow. Because of vibration,
shock is always more devastating than if the same force were applied
gradually.
VibrationAnalysis(ModalAnalysis)Byits very nature, vibration involves repetitive motion. Each occurrence
ofacompletemotionsequenceiscalleda“cycle.”Frequencyisdefinedas
so many cycles in a given time period. “Cycles per seconds” or “Hertz”.
Individual parts have what engineers call “natural” frequencies. For
example,aviolinstringatacertaintensionwillvibrateonlyataset
numberoffrequencies,whichiswhyyoucanproducespecificmusicaltones.
There is a base frequency in which the entire string is going back and
forthinasimplebowshape.
Harmonicsandovertonesoccurbecauseindividualsectionsofthestringcan
vibrateindependentlywithinthelargervibration.Thesevariousshapesare
called “modes”. The base frequency is said to vibrate in the first mode,
andsoonuptheladder.Eachmodeshapewillhaveanassociatedfrequency.
Higher mode shapes have higher frequencies. The most disastrous kinds of
consequencesoccurwhenapower-drivendevicesuchasamotorforexample,
produces a frequency at which an attached structure naturally vibrates.
This event is called “resonance.” If sufficient power is applied, the
attached structure will be destroyed. Note that ancient armies, which
normallymarched“instep,”weretakenoutofstepwhencrossingbridges.
Shouldthebeatofthemarchingfeetalignwithanaturalfrequencyofthe
bridge, it could fall down. Engineers must design so that resonance does
notoccurduringregularoperationofmachines.Thisisamajorpurposeof
Modal Analysis. Ideally, the first mode has a frequency higher than any
potential driving frequency. Frequently, resonance cannot be avoided,
especiallyforshortperiodsoftime.Forexample,whenamotorcomesupto
speed it produces a variety of frequencies. So it may pass through a
resonantfrequency.
BucklingAnalysisIfyoupressdownonanemptysoftdrinkcanwithyourhand,notmuchwill
seemtohappen.Ifyouputthecanonthefloorandgraduallyincreasethe
forcebysteppingdownonitwithyourfoot,atsomepointitwillsuddenly
squash.Thissuddenscrunchingisknownas“buckling.”
Modelswiththinpartstendtobuckleunderaxialloading.Bucklingcanbe
defined as the sudden deformation, which occurs when the stored
membrane(axial)energyisconvertedintobendingenergywithnochangein
the externally applied loads. Mathematically, when buckling occurs, the
totalstiffnessmatrixbecomessingular.
In the normal use of most products, buckling can be catastrophic if it
occurs.Thefailureisnotonebecauseofstressbutgeometricstability.
Oncethegeometryofthepartstartstodeform,itcannolongersupport
even a fraction of the force initially applied. The worst part about
buckling for engineers is that buckling usually occurs at relatively low
stressvaluesforwhatthematerialcanwithstand.Sotheyhavetomakea
separatechecktoseeifaproductorpartthereofisokaywithrespectto
buckling.
Slender structures and structures with slender parts loaded in the axial
direction buckle under relatively small axial loads. Such structures may
fail in buckling while their stresses are far below critical levels. For
suchstructures,thebucklingloadbecomesacriticaldesignfactor.Stocky
structures, on the other hand, require large loads to buckle, therefore
bucklinganalysisisusuallynotrequired.
Buckling almost always involves compression; refer to Figure-3. In
mechanicalengineering,designsinvolvingthinpartsinflexiblestructures
like airplanes and automobiles are susceptible to buckling. Even though
stress can be very low, buckling of local areas can cause the whole
structuretocollapsebyarapidseriesof‘propagatingbuckling’.Buckling
analysis calculates the smallest (critical) loading required buckling a
model. Buckling loads are associated with buckling modes. Designers are
usually interested in the lowest mode because it is associated with the
lowest critical load. When buckling is the critical design factor,
calculatingmultiplebucklingmodeshelpsinlocatingtheweakareasofthe
model. This may prevent the occurrence of lower buckling modes by simple
modifications.
Figure-3.Bucklingexample
ThermalanalysisThere are three mechanisms of heat transfer. These mechanisms are
Conduction, Convection and Radiation. Thermal analysis calculates the
temperaturedistributioninabodyduetosomeorallofthesemechanisms.
Inallthreemechanisms,heatflowsfromahigher-temperaturemediumtoa
lowertemperatureone.Heattransferbyconductionandconvectionrequires
thepresenceofaninterveningmediumwhileheattransferbyradiationdoes
not.
Therearetwomodesofheattransferanalysis.
SteadyStateThermalAnalysisInthistypeofanalysis,weareonlyinterestedinthethermalconditions
ofthebodywhenitreachesthermalequilibrium,butwearenotinterested
inthetimeittakestoreachthisstatus.Thetemperatureofeachpointin
the model will remain unchanged until a change occurs in the system. At
equilibrium,thethermalenergyenteringthesystemisequaltothethermal
energyleavingit.Generally,theonlymaterialpropertythatisneededfor
steadystateanalysisisthethermalconductivity.
TransientThermalAnalysisInthistypeofanalysis,weareinterestedinknowingthethermalstatus
of the model at different instances of time. A thermos designer, for
example,knowsthatthetemperatureofthefluidinsidewilleventuallybe
equal to the room temperature(steady state), but he is interested in
findingoutthetemperatureofthefluidasafunctionoftime.Inaddition
to the thermal conductivity, we also need to specify density, specific
heat, initial temperature profile, and the period of time for which
solutionsaredesired.
Tillthispoint,wehavelearnedthebasicsofvariousanalysesthatcanbe
performedinSolidWorks.Now,wewilllearnaboutthestudiesthatcanbe
performedinSolidWorks.
DROPTESTSTUDIESDropteststudiessimulatetheeffectofdroppingapartoranassemblyon
arigidorflexiblefloor.Toperformthisstudythefloorisconsideredas
planar and flat. The forces that are considered automatically for this
studyaregravityandimpactreaction.
FATIGUEANALYSISThefatigueismoreoverastudythenanalysis.Butitisgenerallynamed
as analysis. This analysis is used to check the effect of continuous
loadingandunloadingofforcesonabody.Thebaseelementforperforming
fatigueanalysisareresultsofstatic,nonlinear,ortimehistorylinear
dynamicstudies.
PRESSUREVESSELDESIGNSTUDYPressure Vessel Design study allows you combine the results of static
studies with the desired factors and interpret the results. The Pressure
Vessel Design study combines the results of the static studies
algebraicallyusingalinearcombinationorthesquarerootofthesumof
thesquares.
DESIGNSTUDYDesignStudyisusedtoperformanoptimizationofdesign.UsingtheDesign
Studyyoucan:
•Definemultiplevariablesusingsimulationparameters,ordrivingglobal
variables.
•Definemultipleconstraints.
•Definemultiplegoalsusingsensors.
•Analyzemodelswithoutsimulationresults.Forexample,youcanminimize
themassofanassemblywiththevariables,densityandmodeldimensions,
theconstraint,andvolume.
•Evaluatedesignchoicesbydefiningaparameterthatsetsbodiestouse
differentmaterialsasavariable.
Till this point, you have become familiar with the analyses that can be
performed by using SolidWorks. But, do you know how the software analyze
theproblems.TheanswerisFEA.
FEAFEA,FiniteElementAnalysis,isamathematicalsystemusedtosolvereal-
worldengineeringproblemsbysimplifyingthem.InFEAbySolidWorks,the
modelisbrokenintosmallelementsandnodes.Then,distributedforcesare
applied on each element and node. The cumulative result of forces is
calculatedanddisplayedinresults.Theelementsinwhichamodelcanbe
brokenintoaregiveninFigure-4,Figure-5,andFigure-6.
Figure-4.Finiteelementslist1
Figure-5.Finiteelementslist2
Figure-6.Finiteelementslist3
We will be now use the information discussed above in SolidWorks
Simulation.TheprocessofstartingSolidWorksSimulationisgivennext.
STARTINGSOLIDWORKSSIMULATIONBefore you try to start SolidWorks Simulation, make sure that you have
installeditwithSolidWorksandyouappliedtheserialkeyforitduring
installation.Then,followthestepsgivennext.
• Start SolidWorks and open the model for which you want to perform the
analyses.
•ClickontheSolidWorksAdd-InstabandselecttheSolidWorksSimulationbutton;refertoFigure-7.
•Onclickingthisbutton,SimulationtabwillbeaddedintheRibbon.
•ClickontheSimulationtab,theNewStudydrop-downwillbedisplayedintheRibbon.
There are two buttons available in this drop-down;SimulationAdvisor andNewStudy.WewillstartwithSimulationAdvisorasitisgoodfornovicestothesoftware.
Figure-7.SolidWorkssimulationbutton
OnclickingSimulationAdvisor•ClickontheSimulationAdvisorbuttonfromthedrop-down.TheSimulationAdvisorpanewilldisplayintherightoftheSolidWorkswindow;refertoFigure-8.
Figure-8.Simulationadvisorpane
•ReadthetextintheAdvisorandperformtheactionsaccordingly.Thisis
aguidedprocesssoitisrecommendedtoperformsometricksonsoftware
byyourself.Wewilllearnmoreabouttheadvisorlaterinthebook.
OnclickingNewStudy• Click on the New Study button from the drop-down. The StudyPropertyManagerwilldisplay;refertoFigure-9.
Figure-9.StudyPropertyManager
ThebuttonsavailableintheTyperolloutofthePropertyManagerrefertodifferenttypeofanalyses.
Wewilldiscusstheseanalysesonebyoneintheupcomingchapters.
BasicofAnalyses
Chapter2
TopicsCovered
Themajortopicscoveredinthischapterare:
•StartingAnalysis
•ApplyingMaterial
•DefiningFixtures
•Applyingloads
•DefiningConnections
•SimulatingAnalysis
•Interpretingresults
STARTINGANALYSISTherearetwomethodstostartananalysisinSolidWorksSimulation;using
StudyAdvisorandusingNewStudybutton.WewillusetheNewStudybuttonthroughout the book. Although we will give short notes for using StudyAdvisor to perform the analyses. The steps to start static analysis aregivennext.
• Click on theNewStudy button from the Study Advisor drop-down in theSimulationtabofRibbon.TheStudyPropertyManagerwilldisplay.
•ClickontheStaticbuttonfromthePropertyManagerandspecifythenameofanalysisasdesiredintheNamerollout.
• Click on theOK button from the PropertyManager. The interface willdisplayasshowninFigure-1.
Figure-1.Staticanalysisinterface
Thefirststepforthisanalysisistoapplymaterialonthemodel.
APPLYINGMATERIALMaterial is a key input for any analysis. The result of analysis is
directly related to material of the object. There are few properties of
materiallike,ultimatestrength,hardness,andyoung’smoduluswhichplay
importantroleinsuccess/failureoftheobjectunderspecifiedload.Also,
materialdeterminestheapplicationofobjectinrealworld.Forexample,
wedonotuseglasstomakepistonsinengine.Thestepstoapplymaterial
onobjectaregivennext.
•ClickontheApplyMaterialbuttonfromtheSimulationtabintheRibbon.TheMaterialdialogboxwilldisplayasshowninFigure-2.
Figure-2.Materialdialogbox
Alibraryofstandardmaterialsisavailableinthisboxforselection.
• Select the desired material from left pane of the box. The related
parameterswillbedisplayedattheright.
•ClickontheApplybuttontoapplythematerial.
•ClickontheClosebuttontoclosethebox.
Although,wehaveabiglibraryofstandardmaterialsavailablebutstill
there is always a need to custom material. Now, we will discuss about
addingcustommaterialsinlibrary.
AddingCustomMaterialsBig researches are going on to enhance the properties of engineering
materialstomakethemlighterandstronger.Duringyourjob,youmaycome
across a material whose properties are not available in the library. In
suchacase,followthestepsgivennexttocreatecustommaterial.
• Right-click on theMaterial option from theFeatureManagerDesignTreeand select the Edit Material option from the short-cut menu displayed;
refertoFigure-3.TheMaterialdialogboxwillbedisplayedasshowninFigure-2earlier.
Figure-3.EditMaterialoption
• Right-click on the material whose properties are close to the material
you want to create and select theCopy option from the shortcut menudisplayed;refertoFigure-4.
Figure-4.Copyoptionformaterial
•Now,movetothebottomofmateriallistandexpandtheCustomMaterialcategory;refertoFigure-5.
Figure-5.CustomMaterialcategory
•Right-clickontheCustomMaterialscategoryandselecttheNewCategoryoptiontoaddanewsub-categoryinit.Specifythedesiredname;referto
Figure-6.
•Right-clickonthenewsub-categoryandselectthePasteoptionfromtheshortcutmenu;refertoFigure-7.Thecopiedmaterialwillbeaddedinthe
sub-categorybutwiththeedit-ablefeatures.Notethatyoucanstartwith
a completely new material by using theNewMaterial option in place ofPasteoption.
Figure-6.Newcategoryadded
Figure-7.Pasteoptionformaterials
•Clickontheaddedmaterial,theoptionsrelatedtothematerialswillbe
displayedontherightindialogbox;refertoFigure-8.
•Clickintheeditboxesandspecifythedesiredvalues.
• Click on theSave button to save the parameters and then click on theClose button. Now, you can use this custom material like standard
materials.
Figure-8.Detailsofcustommaterial
DEFININGFIXTURESTo perform any analysis, it is important to fix the object by some
constrainssothattheeffectofappliedforcescanbechecked.Ifyoudo
notapplyfixturesthentheobjectwillbefreetomoveinthedirectionof
forces applied and no stress or strain will be induced in it. There are
variousoptionsforconstraintheobject.Alltheseoptionsareexplained
next.
FixturesAdvisorThisbuttonisusedtocreatefixturesinaguidedway.Aninteractivetask
paneisusedtoapplyfixturesonthebasisofyourresponses.Thestepsto
usethistoolaregivennext.
•ClickontheFixturesAdvisorbuttonfromtheFixturesAdvisordrop-downinthe Ribbon. The Simulation Advisor will display in the right of the
window;refertoFigure-9.
• Click on theAdd a fixture option from the SimulationAdvisor pane. TheFixturePropertyManagerwillbedisplayed;refertoFigure-10.
Figure-9.SimulationAdvisor
Figure-10.FixturePropertyManager
Note that the options displayed in the PropertyManager can be directlychosenfromtheFixtureAdvisordrop-downintheRibbon;refertoFigure-11.Various options in the PropertyManager and the drop-down are discussed
next.
Figure-11.FixturesAdvisordrop-down
FixedGeometryThisisthemostcommonlyusedfixturetype.Usingthisfixturetype,you
can fix the face, edge or point of the object. To apply this fixture,
followthestepsgivennext.
•ClickontheFixedGeometry button from theFixturesAdvisor drop-down.TheFixturePropertyManagerwilldisplayasshowninFigure-10.
• Make sure that the Fixed Geometry button is selected in the Standard(FixedGeometry)rollout.
•Selectthefacethatyouwanttobefixed;refertoFigure-12.
Figure-12.Faceselectedforfixing
•ClickOKbuttontodefinethefixture.
YoucanalsosplitafacebeforeclickingOKtopreciselydefinethefixed
area.Thestepstodosoaregivennext.
• Click on the Split tab from the Fixture PropertyManager. The
PropertyManagerwilldisplayasshowninFigure-13.
•ClickontheCreateSketchbuttonfromthePropertyManager.Youareaskedtoselectaplane/faceforsketchingifnotselectedearlierforcreating
fixture.
•Selectthedesiredplanetosketchthesplittingline.
• Create the splitting line by using theLine tool; refer to Figure-15.Notethatyoucancreateanydesiredshapebyusingthetoolsactivein
theRibbon;refertoFigure-14.
Figure-13.FixturePropertyManagerwithsplittab
Figure-14.Sketchcreatedforsplitting
•ClickontheExitSketchbuttondisplayedinSplitboxinviewport.Youareaskedtoselectaface.
•Selectthefacesthatyouwanttosplitbytheprojectionofdrawnsketch
line;refertoFigure-16.
Figure-15.Splittinglinedrawn
Figure-16.Facesselectedforsplitting
• Click on the Create Split button from the Selection rollout of the
PropertyManager.Theselectedfaceswillgetsplit;refertoFigure-17.
Figure-17.Facesaftersplitting
•ClickontheTypetabofthePropertyManagertodisplayoptionsrelatedtofixture.
• Click on the faces that you want to fix and remove unwanted faces by
right-clicking and then selecting the Delete option from the shortcut
menu;refertoFigure-18.
Figure-18.Splittedfacesselectedforfixing
•ClickonOKbuttonfromthePropertyManagertofixthefaces.
Where should we use the FixedGeometry fixture? The answer is: we usethisconstraintwhereweknowthattheselectedfaceislyingonahardsurfaceandit cannot move due to action of any applied forces. A live example can be a
buildingfixedtoearthbyitsbase.Weexpectthebuildingnottomoveif
loadincreasesduetosomeunexpectedguests.
Figure-19.FixturePropertyManagerforrollersliderfixture
Roller/SliderThisoptionisusedtofixafaceinsuchawaythatitcanslide/rollin
itsplanebutcannotmoveperpendiculartotheplane.Thestepstofixa
facebyusingthisoptionaregivennext.
•ClickontheRoller/SliderbuttonfromtheFixturesAdvisordrop-down.TheFixture PropertyManager will be displayed similar to the one discussedearlierbutwiththeRoller/Sliderbuttonselected;refertoFigure-19.
•Selectthefacethatyouwanttoallowforslidingorrolling.Referto
Figure-20.
•ClickontheOKbuttonfromthePropertyManagertoapplythefixture.
Figure-20.Sliderfaceselection
Herethequestioncomes,whereshouldweusetheRoller/Sliderfixture?Theansweris:weusethisconstraintwhereobjectcanrollorslideonasurfacebutcannotmovenormaltoit.AliveexamplecanbeTyreofanautomobilewhichrolls on the road and it is expected not to move up towards the sky or
down.
FixedHingeThisoptionisusedtofixacylindricalfaceinsuchawaythattheface
acttobehinged.Thestepstoapplyhingefixturearegivennext.
• Click on the Fixed Hinge tool from the Fixtures Advisor drop-down. TheFixture PropertyManager will be displayed with the Fixed Hinge button
selected;refertoFigure-21.
•Selectacylindricalfacethatyouwanttofixashinge;refertoFigure-
22.
•ClickontheOKbuttontoapplythefixture.
Figure-21.FixturePropertyManagerforfixedhingefixture
Figure-22.Faceselectedforhinge
WhereshouldweusetheFixedHingefixture?Theansweris:weusethisconstraintwhereobjectcanrevolvearound itsaxis.Aliveexamplecanbecarhood(alsocalledcarbonnetinsomeregionsofworld).
ElasticSupport
Thisoptionisusedtoinsertanelasticsupportbetweenfloorandobject.
Thistypeoffixtureisgenerallyappliedtorubberorplasticparts.The
stepstoapplythisfixturearegivennext.
• Click on theElastic Support button from theFixtures Advisor drop-down.TheConnectorPropertyManagerwilldisplayasshowninFigure-23.
Figure-23.ConnectorsPropertyManager
• Select the face that you want to make as elastic support; refer to
Figure-24.
•Clickinthedrop-downofStiffnessrollouttospecifythetypeofunitstobeusedtospecifythevalueofstiffness.
• Select the desired option from the SI, English (IPS), and Metric (G)option.
• Click in the Normal edit box and specify the stiffness of elastic
supportinnormaldirectiontotheselectedface.
• Click in theShear edit box and specify the value of stiffness in thelateraldirection(alsoknownasstiffnessinsheardirection).
• You can specify the total stiffness in normal and shear direction by
selecting theTotal radio button in place ofDistributed in the Stiffnessrollout.
•ClickontheOKbuttontodefinethefixture.
Figure-24.Selectingfaceforelasticsupport
Where should we use the Elastic Support fixture? The answer is: we usethisconstraintwhereobject isplacedor fastenedona soft surface likewoodorrubber.Aliveexamplecanbeanobjectplacedonwood,rubberoranyspringbase.Ihopeyouhaveseenkidsjumpingonthebed,theyreboundbecauseof
elasticpropertyofmattressonbed.
Figure-25.Advancedfixtureoptions
AdvancedFixturesThere are some advanced fixtures available in SolidWorks Simulation for
constraining the objects. To apply these fixtures follow the steps given
next.
•ClickontheAdvancedFixturesbuttonfromtheFixturesAdvisordrop-downintheRibbon.TheFixturePropertyManagerwillbedisplayedasshowninFigure-25.
TheoptionsavailableinthisPropertyManagerarediscussednext.
SymmetryTheSymmetrybuttonisusedtosimplifythegeometryofthemodelbeinganalyzed. This option gives us freedom to analyze half of the body and
hence reducing size of the problem. Based on this result the effect on
whole body can be analyzed. This option is not recommended if you are
performingbucklingorfrequencystudies.Thestepstousethisoptionare
givennext.
•ClickontheSymmetrybuttonfromthePropertyManager.Youareaskedtoselectafacetodefinesymmetry.
•Selectthefacethatissymmetrichalforquarterofthemainpart.Refer
toFigure-26.Notethatyoucancreateanalyzeapartusingquarterofit
ifthepartissymmetricandotherloadingconditionsaresameforfull
part.Tousequarterpart,youwillberequiredtoselecttwofacesfor
definingsymmetry;refertoFigure-27.
Figure-26.Symmetricfixtureapplication
Figure-27.Partsymmetryusingquartersection
•ClickontheOKbuttonfromthePropertyManagertoapplythefixture.
Where should we use the Symmetry fixture? The answer is: we use thisconstraintwhereobjectissymmetricaboutaplaneorface.Theliveexamplecanbeaflattablewhichcanbedividedintotwoorfoursamesections.
CyclicSymmetryThisbuttonisusedtocreatesymmetryforcircularobjects.Notethatthe
parts that can be used for circular symmetry are generally created by
Revolve tool and are having an axis for symmetry. The steps to use thisoptionaregivennext.
•ClickontheCyclic Symmetry button from thePropertyManager. You areaskedtoselectstartingfaceforcircularsymmetry;refertoFigure-28.
Selectthedesiredface.
Figure-28.Faceselectionforcyclicsymmetry
•ClickinthenextboxinPropertyManagerandselecttheendingfaceforcircular symmetry. Similarly, click in the axis selection box in
PropertyManager and then select the axis about which the part is
symmetric. Preview of symmetry will be displayed as shown in Figure-29.
Note that the axis should have been created byAxis tool inReferenceGeometrydrop-downintheAnalysisPreparationCommandManager.
Figure-29.Previewofsymmetryfixture
•ClickontheOKbuttontoapplythecircularsymmetryfixture.
Where shouldweuse theCyclicSymmetry fixture?Theansweris:weusethisconstraintwhereobjectcanbecreatedbysymmetricblockssharingthesameaxis.Aliveexamplecanbealloywheels.
UseReferenceGeometryThis button is used to fix the linear/rotational degree of freedom of a
body.Therotationalconstraintcanbeappliedonshellsandbeamsonly.To
applythisfixture,followthestepsgivennext.
Figure-30.FixturePropertyManagerwithUseReferenceGeometrybuttonselected
• Click on the Use Reference Geometry button from the FixturePropertyManager. The options in the PropertyManager will display as
showninFigure-30.
•Selectafaceonwhichyouwanttoapplythefixture.Notethatyoucan
alsoselectanedgeorvertexforfixture.
•ClickinthenextselectionboxinPropertyManagerandselectanedgeorfacetodefinethedirectionreference.
•ClickintheUnitdrop-downintheTranslationsdrop-downandselectthedesiredunittype.
• Click on the desired direction button from rollout and specify the
distancelimittowhichtheselectedfacecanmove/rotate.
•Thedirectionsforwhichbuttonsarenotselectedarefree.
OnFlatFacesThisbuttonisusedtofixaflatfaceinthedesireddirection.Youcan
also specify the distance limit in specific directions by using this
option.Thestepstousethisbuttonaregivennext.
•ClickontheOnFlatFacesbuttonfromtheFixturePropertyManager. ThePropertyManagerwilldisplayasshowninFigure-31.
•Selectthefacefromthemodelthatyouwanttofix.
• Click on the button of direction in which you want to specify the
distancelimit.
•Specifythedesireddistanceintheeditbox.Ifyouwanttofixthebody
inadirectionthenspecifythevalueas0.•Youcanclickonmorethanonebuttontoconstrainmoredirections;refer
toFigure-32.
Figure-31.FixturePropertyManagerwithOnFlatFacesbutton
Figure-32.Previewofonflatfacesfixture
•ClickontheOKbuttonfromthePropertyManagertoapplythefixture.Figure-33.FixturePropertyManageronselectingOnCylindricalFacesbutton
OnCylindricalFacesThis button is used to fix a cylindrical face in the desired direction.
ThisoptionworksinthesamewayasOnFlatFacesbuttonworks.Thestepstousethisoptionaregivennext.
• Click on the On Cylindrical Faces button. The options in the
PropertyManagerwilldisplayasshowninFigure-33.•Selectthecylindricalfaceofthemodelandselectthebuttonsforthe
directionsforwhichyouwanttoconstrainthebodymovement.
• Specify the distance/rotation limit for the body for the selected
directionbuttons.RefertoFigure-34.
Figure-34.Previewofoncylindricalfacesfixture
OnSphericalFacesThisbuttonisusedtofixasphericalfaceinthedesireddirections.This
option works in the same way as On Cylindrical Faces option. The only
differenceisthatyouneedtoselectsphericalfaceforOnSphericalFacesoption.Restoftheprocedureissame.RefertoFigure-35.
Now,youknowallthetypeoffixturesavailableinSolidWorksSimulation.
Thenextstepistoapplytheforcesontheobjects.
Figure-35.Previewofonsphericalfacesfixture
EXTERNALLOADADVISORTheoptionsinthisdrop-downareusedtoapplyvarioustypesofforceson
thebody.Theoptionsinthedrop-downarediscussednext.
ExternalLoadAdvisorThisoptionisusedtodisplaytheSimulationAdvisorwiththepagerelatedtoforce.Thestepstousethisoptionaregivennext.
•ClickontheExternalLoadsAdvisoroptionfromtheExternalLoadAdvisordrop-downintheSimulationtaboftheRibbon.TheSimulationAdvisorwilldisplayintherightofthescreenasshowninFigure-36.
•ClickontheAdda loadlinkbuttonfromtheadvisortoapplytheload.The options related to forces will displayed in the Force/TorquePropertyManager; refer to Figure-37. You can display the same
PropertyManagerbyusingtheForcetoolfromtheExternalLoadsAdvisordrop-downintheRibbon.Themethodisdiscussednext.
ForceThis is the mostly used option in SolidWorks Simulation for applying
forces.Toapplytheforces,followthestepsgivennext.
•ClickontheForceoptionfromtheExternalLoadsAdvisordrop-downintheRibbon. The Force/Torque PropertyManager will display as shown in
Figure-37.
Figure-36.SimulationAdvisorwithoptionsforload
Figure-37.ForceTorquePropertyManager
•Selectthefaceonwhichyouwanttoapplytheforce.
•Tochangethedirectionofforce,selecttheSelecteddirectionradiobuttonfrom the PropertyManager. You will be asked to select reference for
directionviaapinkselectionbox;refertoFigure-38.
• Click in this selection box and select a reference to specify the
directionofforce;refertoFigure-39.Notethatyouneedtoselectthe
force vector buttons from the Force rollout in the PropertyManager toapplyforcesindesiredcomponentofselecteddirection.
Figure-38.Forceinselecteddirection
Figure-39.Forceappliedinselecteddirection
• If you have selectedNormal radio button in thePropertyManager thenclickintheForceValueeditboxandspecifythedesiredvalue.
•Youcanchangetheunittypebyselectingdesiredoptionfromthedrop-
downintheForce/Torquerollout.• If you have non uniform distribution of force and have an equation of
distribution then click on the check box of Nonuniform Distributionrollout. The options related to Non-uniform distribution of force will
display;refertoFigure-40.
Figure-40.Nonuniformforcedistribution
• There are three coordinate systems to define the equation, Cartesian
CoordinateSystem,CylindricalCoordinateSystem,andSphericalCoordinate
System.SelectthedesiredbuttonfromtheTypeofCoordinateSystemarea
ofrollout;refertoFigure-41.
Figure-41.Coordinatesystemselection
• Click on the Edit Equation button from the rollout. The Edit Equationdialogboxwillbedisplayedaspertheselectedcoordinatesystem;refer
toFigure-42.
Figure-42.EditEquationdialogbox
SetthedesiredequationofforceintheeditboxinEditEquationdialog
box.Anexampleofsuchequationisgivennext:
F(X,Y,Z)=A+B*”X”+C*”Y”+D*”X”*”Y”+E*”X”^2+F*”Y”^2+G*”Z”^2
•Inthisequation,youneedtoenterthenumericalvaluesofA,B,C,D,
E,FandG.
• Note that the variables of equation which are x, y, and z in case of
Cartesian;r,t,andzincaseofCylindrical;andr,t,andpincaseof
SphericalCoordinateSystemshouldbeclosedinquotationmarks(““).
•Afterspecifyingtheequation,clickontheOKbuttonfromthedialog
box.
•ClickintheCoordinateSystemselectionboxandthenselectthedesired
coordinatesystemfromtheviewport.
•ClickontheOKbuttonfromthePropertyManagertoapplytheforce.
TorqueTechnicallyTorqueisproductofforceanddistance.Ifforceisappliedon
anobjectinsuchawaythatittendtorotatetheobjectthenitiscalled
torque.Thestepstoapplytorquearegivennext.
•ClickontheTorquebuttonfromtheExternalLoadsAdvisordrop-down.TheForce/Torque PropertyManager will be displayed with the Torque button
selectedbydefault.RefertoFigure-43.
•Selecttheroundfaceonwhichyouwanttoapplytorque.Previewofthe
torquewilldisplay;refertoFigure-44.
Figure-43.ForceTorquePropertyManagerwithtorqueoptions
Figure-44.Previewoftorqueapplied
• Specify the desired value of torque in the Torque Value edit box of
Force/Torquerollout.
• The other options in this PropertyManager are same as discussed for
force.ClickontheOKbuttonfromthePropertyManagertoapplytorque.
PressurePressureistheforceappliedperunitarea.Generally,weapplypressure
when we are analyzing pressure vessels or pipes. The steps to apply
pressurearegivennext.
• Click on thePressure option from theExternal LoadsAdvisor drop-down.ThePressurePropertyManagerwilldisplayasshowninFigure-45.
• Select the desired radio button from the Type rollout to specify thedirection of pressure. If you select the Use reference geometry radio
buttonthenonemoreselectionboxwillbedisplayedintheTyperolloutallowingyoutoselectthedirectionreference.
• Select the face on which you want to apply the pressure and enter the
desiredvalueofpressureintheeditboxdisplayedinthePressureValuerollout.
•IfyouhaveselectedtheUsereferencegeometryradiobuttonthenselectthedirectionreferencetospecifythedirectionofpressure.Previewof
thepressureappliedwillbedisplayed;refertoFigure-46.
•ClickontheOKbuttonfromthePropertyManagertoapplythepressure.Figure-45.PressurePropertyManager
Figure-46.Previewofpressureapplied
GravityGravityistheforceexertedbyearthoneachobjectinearthzone.Thisis
the force that causes objects to fall on the floor. TheGravity tool inSolidWorks Simulation is used to apply the gravity force on objects. The
stepstousethistoolaregivennext.
•ClickontheGravitytoolfromtheExternalLoadsAdvisordrop-down.TheGravityPropertyManagerwillbedisplayedasshowninFigure-47.
•Selecttheplane/face/edgetowhichdefinethedirectionofgravitational
force. Preview of the gravitational force will be displayed; refer to
Figure-48.
•Select/cleartheReversedirectionasperyourrequirement.Figure-47.GravityPropertyManager
Figure-48.Previewofgravitationalforce
•Ifyouwanttospecifymorecomponentsofgravitationalforcethenexpand
theAdvancedrolloutandenterthevaluesfortwootherdirectionvectorsofgravitationalforce;refertoFigure-49.
•ClickOKtoapplytheforce.
Figure-49.Previewofgravitationalforceadvanced
CentrifugalForceCentrifugal force is a force which causes the rotating objects to move
outward,seeaMary-go-round.IfyourunaMary-go-roundbeyonditsdesign
limits then you can see linked seats coming outward. This force is
generally generated by rotation of bodies. The steps to apply this force
aregivennext.
•ClickontheCentrifugalForcebuttonfromtheExternalLoadsAdvisordrop-down.TheCentrifugalPropertyManagerwilldisplayasshowninFigure-50.
Figure-50.CentrifugalPropertyManager
•Selecttheroundfaceonwhichyouwanttoapplythecentrifugalforce.
• Click in theAngularVelocity edit box and specify the angular velocityi.e.omegafortheobject.
• Click in the Angular Acceleration edit box and specify the value of
angularacceleration.Previewofthecentrifugalforcewilldisplay;refer
toFigure-51.
Figure-51.Previewofcentrifugalforce
•ClickontheOKbuttonfromthePropertyManagertoapplytheforce.
BearingLoad
Bearing load is the load exerted by shaft floating in the inner ring of
bearing. The bearing load is applied on the round face of bearing and
shaft.Thestepstoapplytheloadaregivennext.
• Click on theBearingLoad option from theExternal Loads Advisor drop-down. The Bearing Load PropertyManager will be displayed as shown in
Figure-52.
Figure-52.BearingLoadPropertyManager
•Selectthefacesonwhichyouwanttoapplythebearingload.Notethat
youneedtoselecttwofaces,onefromshaftandonefrombearing.Also,
theselectedfacesmustbehalfofthefullface;refertoFigure-53.Note
thatyouwillneedtheSplitLinetooltodividethefaceofbearingandshaft.
Figure-53.Exampleforbearingload
•SpecifythevalueofloadinX-directionbyusingtherespectiveeditbox
inBearingLoadrollout.• If you want to apply load in Y-direction in place of X-direction then
clickonthe buttonandspecifythevalue.
•Ifyouwanttochangethedirectionasperyourrequirementthenclickin
thepinkselectionboxandselectthedesiredcoordinatesystem.
• Select theSinusoidal distribution orParabolic distribution radio button asperyourrequirement.
•ClickontheOKbuttonfromthePropertyManagertoapplythebearingload.
RemoteLoads/MassRemoteload/massisusedtoapplyforceonanobjectinsuchawaythatthe
originofforceissomewhereelsebutitisalsoaffectingontheselected
face;refertoFigure-54.
Figure-54.Remoteloadexample
If we apply this load in Solidworks Simulation then it will display as
showninFigure-55.
Figure-55.Remoteloadapplied
Theproceduretoapplyremoteloadisgivennext.
• Click on the Remote Load/Mass option from the External Loads Advisordrop-down. TheRemote Loads/Mass PropertyManager will be displayed asshowninFigure-56.
Figure-56.RemoteLoadsorMassPropertyManager
•SelectthedesiredradiobuttonfromtheTyperollouttospecifythetypeofremoteload/massyouaregoingtoapply.Notethatincaseofremote
load, the exact force working on the selected face is dependent on the
totalforceappliedontheactionpointanddistanceofactionpointfrom
the face. If you select theLoad (Direct transfer) radio button then theexactamountloadwhichcomesaftercalculationisappliedontheselected
faces.IfyouselecttheLoad/Mass(RigidConnection)radiobuttonthentheloadappliedontheselectedfaceactsliketheloadispassedwiththe
helpofrigidbarstotheselectedface.IfyouselecttheDisplacement(RigidConnection) radio button then it connects the remote location, atwhichtranslationandrotationsareapplied,tothecenteroftheselected
facesbyarigidbar.Theselectedentitiesdeformaccordingly.
•AfterselectingthedesiredradiobuttonfromTyperollout,clickontheUserDefinedradiobuttonfromtheReferenceCoordinateSystemrolloutand
thenselectareferencecoordinatesystemasrequired.Notethatyoucan
selecttheGlobalradiobuttontouseGlobalCoordinateSystemifyoudonotwishtoselectanyuserdefinedcoordinatesystem.
• Specify the location of remote point by using the edit boxes in the
LocationrolloutinthePropertyManager;refertoFigure-57.
Figure-57.Remoteloadlocation
•Similarly,specifythevalueofforceineachdirectionandthenclickon
theOK button from the PropertyManager to apply the forces. You canalso specify the moment of force by using the options in theMomentrollout.
DistributedMassUsingthisoption,youcanaddthemassoftheobjectsthatarenotcreated
inthemodelsbuttheirmasshaseffectsontheanalysis.Thestepstouse
thisoptionaregivennext.
•ClickontheDistributedMassbuttonfromtheExternalLoadsAdvisordrop-down.TheDistributedMassPropertyManagerwilldisplay;refertoFigure-58.
Figure-58.DistributedMassPropertyManager
•Selectthefaceonwhichyouwanttoaddmassofremoteobject.
• Click in theDistributed Mass edit box and specify the desired value.Previewoftheappliedmasswillbedisplayed;refertoFigure-59.
Figure-59.Previewofdistributedmass
• Click on the OK button from the PropertyManager to apply the
distributedmass.
Temperature
Thisoptionisusedtosettemperatureoftheselectedface.Thisoptionis
mostly used in thermal analyses. The steps to use this option are given
next.
• Click on the Temperature button from the External Loads Advisor drop-
down. TheTemperature PropertyManager will display as shown in Figure-60.
Figure-60.TemperaturePropertyManager
•Selectthefaceforwhichyouwanttosetthetemperature.
•ClickintheTemperatureeditboxoftheTemperaturerolloutandspecifythedesiredvalueintheeditbox.Previewoftheappliedtemperaturewill
bedisplayed;refertoFigure-61.
Figure-61.Previewoftemperature
•YoucanapplytemperatureonalltheexposedfacesbyselectingtheSelectallexposedfacesbutton.
FlowEffects/ThermalEffectsThese option are used to add the fluid flow or thermal effects in the
current study. The steps to specify the flow effect setting and thermal
effectsettingsaregivennext.
Figure-62.FlowThernalEffectstabofStaticdialogbox
•ClickontheFlowEffectsorThermalEffectsbuttonfromtheExternalLoadsAdvisordrop-down.AdialogboxwillbedisplayedwiththeFlow/ThermalEffectstabselected;refertoFigure-62.
• This dialog box is divided into two areas: Thermal options and Fluidpressureoptions.Theoptionsintheseareasarediscussednext.
ThermaloptionsTheoptionsinthisareaareusedtospecifythesourcefortemperaturesin
theactivestudy.Therearethreeoptionstodothat:
InputTemperatureSelectthisradiobuttontomanuallyspecifythetemperatureforthestudy.
Whenusingthisoption,makesuretospecifytemperaturesoncomponentsor
shells.Specifyingtemperaturesontheboundaryonlymaynotbepractical
since a temperature of zero is assumed at all other locations. If you
define temperature on boundary only, you may need to create and solve a
thermalstudyfirsttocomputetemperaturesatallnodes.
TemperaturesfromthermalstudySelectthisoptiontousetheoutputtemperatureofathermalstudyalready
performed.Onselectingthisradiobutton,theoptionsbelowitwillbecome
active. Select the desired thermal study from the drop-down to get is
outputtemperature.Youcanalsosetthetimeforgettingthetemperature
ataspecificpointoftime.Foratransientthermalstudy,selecteithera
Time step number (to import a single temperature) or For each nonlinear
time step, use temperature from corresponding time of transient thermal
analysis.
TemperaturesfromSolidWorksFlowSimulation
SelectthisoptiontousetheoutputtemperatureofacompletedSolidWorksFlowSimulationonthesameconfiguration.Clickonthisradiobuttonandthen click on the Browse button to select the result file of flow
simulation.Selectthedesiredresultfile(*.fld)thathasbeengenerated
by Flow Simulation. Model name, configuration name, and time step number
associatedwiththespecifiedfilearedisplayed.
ReferencetemperatureatzerostrainThiseditboxisusedtosetthetemperatureatwhichnostrainsexistin
themodel.
FluidpressureoptionTheoptionsinthisareaareusedtoimportsfluidpressureloadsfroma
SolidWorksFlowSimulationresultsfile.
IncludefluidpressureeffectsfromFlowSimulationSelectthisoptiontousetheoutputpressurefromacompletedSolidWorks
Flow Simulation results file. On selectin this option the Browse button
will become active below it. Click on the button and select the desired
resultfile(*.fld)thathasbeengeneratedbyFlowSimulation.Forproper
acquisition of pressure loads from Flow Simulation, the active study and
theFlowSimulationstudyshouldbeassociatedwiththesameconfiguration.Tocreatethe*.fldfile,clickFlowSimulation>Tools>ExportResults toSimulation.
Usereferencepressure(offset)in.fldfileSelect this option to use the reference pressure defined in the Flow
Simulationresultsfile.
Definereferencepressure(offset)Selectthisoptiontospecifyareferencepressuredirectly.Thispressure
valueissubtractedfromtheimportedpressurevalues.
Runaslegacystudy(excludeshearstress)Using this option, you can imports only the normal component of the
pressureloadfromtheFlowSimulation.
If you are analyzing an assembly, then you need to specify the type of
connections between various components of the assembly. The options to
specify connections for assembly are available in theConnectionsAdvisordrop-downwhichisdiscussednext.
CONNECTIONSADVISORThe options in this drop-down are used to apply various types of
connections between assembly components. You can also specify the
connections between components and ground by using these options. These
optionsarediscussednext.
ConnectionsAdvisorThis option is used to display the page of Simulation Advisor that is
relatedtoconnectionsbetweenassemblycomponents.Thestepstousethis
optionaregivennext.
•ClickontheConnectionsAdvisorbuttonfromtheConnectionsAdvisordrop-down in the Ribbon. The Simulation Advisor will be displayed with the
optionstoapplyconnections;refertoFigure-63.
Figure-63.SimulationAdvisorwithoptionsforconnections
•ClickontheNextbuttonfromtheSimulationAdvisor.Thelistofoptionsthatcanbeusedforconnectionsaredisplayed.
• Select the desired option and follow the instructions given by the
software. Note that these options are also available in the Connections
Advisordrop-downintheRibbon.Theoptionsarediscussedinthenext.
ContactSetsThisoptionisusedtospecifythecontacttypebetweentwocomponentsora
componentandground.Thestepstousethisoptionaregivennext.
•ClickontheContactSetsbuttonfromtheConnectionsAdvisor drop-down.TheContactSetsPropertyManagerwilldisplayasshowninFigure-64.
Figure-64.ContactSetsPropertyManager
•SelecttheAutomaticallyfindcontactsetsoptionfromtheContactrolloutifyouwantthesoftwaretoautomaticallydecidethetypeofcontacttobe
applied.
• Select theManually select contact sets option to specify the connectionsmanually.
• On selecting theManually select contact sets option, two selection boxeswillbecomeavailable.
• Select the desired option from the drop-down in theType rollout. Theoptionsinthisdrop-downandtheprocessofusingtheseoptionsaregiven
next.
NoPenetrationThisoptionisusedwhenyouwantthefacestobeintouchbyspecifiedgap
valuebutdonotwantthemtopenetratethrougheachother.Thestepsto
usethisoptionaregivennext.
•SelecttheNoPenetrationoptionfromthedrop-downintheTyperollout.TheoptionsinthePropertyManagerwillbedisplayedasshowninFigure-65.
Figure-65.OptionsinContactSetsPropertyManageronselectingNoPenetrationoption
• Click in the blue selection box and select the face/edge/point of the
firstpartthatyouwanttospecifyforconnection.
•Clickinthepinkboxandselecttheface/planeofsecondcomponentor
groundtocreatetheconnectionwith.
•ClickontheFrictioncheckboxandspecifythecoefficientoffrictionforcontact.
•ClickontheGap(clearance)checkboxandspecifythedesiredgapbetweenthetwocomponentsorcomponentandground.
•YoucanselecttheSelf-Contactcheckbox,ifyouwantyourobjecttonotintersectwithitselfundertheapplicationofforce;refertoFigure-66.
ThischeckboxisnewadditioninSolidWorks2015.
Figure-66.ResultofloadwithSelfContactcheckbox
•ClickonthecheckboxforAdvanced rollout and specify the method ofcontactbetweenthecomponentsbyselectingtheappropriateoption.
BondedThisoptionisusedtoattachonecomponenttotheothersuchthatboththe
componentsarepermanentlybondedtoeachother.Inotherwords,effectof
force on one component will also be passed on the bonded component
perfectly.Thestepstousethisoptionaregivennext.
• Select theBonded option from the drop-down in theType rollout. TheoptionsinthePropertyManagerwillbedisplayedasshowninFigure-67.
Figure-67.OptionsinContactSetsPropertyManageronselectingBondedoption
• Click in the blue box and select the face/edge/vertex of the first
component.
•Clickinthepinkboxandselecttheface/planeofthesecondcomponent.
Previewofthebondedconnectionwillbedisplayed;refertoFigure-68.
Figure-68.Previewofbondedconnection
• Click on the OK button from the PropertyManager to create the
connection.
AllowPenetrationThisoptionisusedallowpenetrationofoneobjectwiththeotherobject.
Notethatthisoptionisgenerallyusedwhentheobjectsareductile.The
stepstousedthisoptionaregivennext.
• Select the Allow Penetration option from the drop-down in the Typerollout.TheoptionsinthePropertyManagerwillbedisplayedasshowninFigure-69.
Figure-69.OptionsinContactSetsPropertyManageronselectingAllowPenetrationoption
• Click in the blue selection box and select the face/edge/vertex of the
firstcomponent.
•Clickinthepinkselectionboxandselecttheface/planeofthesecond
component.
•ClickontheOKbuttonfromthePropertyManager.
ShrinkFitShrinkfittingisaprocessinwhichashaftisinsertedinaholethatis
heatedup.Whenthehotholecoolsdownitstronglyarreststheshaftdue
tocontraction.Ifyouneedtospecifysuchaconnectionintheassembly,
thenthisoptionisused.Thestepstousethisoptionaregivennext.
•ClickontheShrinkFitoptionfromthedrop-downintheTyperolloutofPropertyManager. The PropertyManager will be displayed as shown in
Figure-70.
Figure-70.OptionsinContactSetsPropertyManageronselectingShrinkFitoption
•Youcanapplythisoptioninthesamewayasdiscussedearlier.Youcan
alsospecifyfrictioncoefficientbyselectingtheFrictioncheckbox.
VirtualWallUsingthisoption,youcanmakeacomponentattachedtoavirtualwall.In
this case, the body reacts as if it is in contact with a rigid/flexible
wall.Thestepstoapplythiscontactaregivennext.
•SelecttheVirtualWalloptionfromthedrop-downintheTyperollout.TheoptionsinthePropertyManagerwilldisplayasshowninFigure-71.
Figure-71.OptionsinContactSetsPropertyManageronselectingVirtualWalloption
•Selectthefacethatyouwanttoattachwiththevirtualwall.
•Clickinthevioletselectionboxtocollecttheplane.
•Selectthedesiredplanethatyouwanttomakeasvirtualwall.
•ClickontheGap(clearance)checkboxtospecifytheclearancegap.
•ClickontheRigidradiobuttontocreatearigidwallandspecifythefrictioncoefficientforthewallintheeditboxdisplayedinWallTyperollout.
•ClickontheFlexibleradiobuttontocreateaflexiblewall.• Specify the axial stiffness and tangential stiffness in the edit boxes
availableintheWallStiffnessrollout.
ComponentContactWhileworkingonanassembly,thisoptionisgenerallypreferredoverthe
otheroptionsavailableforconnections.Usingthisoption,youcanspecify
the contact between two or more bodies along their all shared faces. The
stepstousethisoptionaregivennext.
•ClickontheComponentContactbuttonfromtheConnectionsAdvisordrop-down.ThePropertyManagerwilldisplayasshowninFigure-72.
Figure-72.ComponentContactPropertyManager
•SelectthedesiredradiobuttonfromtheContactTyperollout.
•SelecttheGlobalContactcheckboxtoapplytheselectedcontacttypetoallthecomponentsoftheassemblyorselectthecomponentsonebyoneto
specifythecontacttype.
•IfyouhaveselectedtheNoPenetrationradiobuttonthenselectthecheckboxofFrictionrolloutandspecifythefrictioncoefficient.
• If you have selected the Bonded radio button from the Contact Typerolloutthenyoucanspecifythetypeofmeshforthecomponents.
•IfyouselecttheCompatiblemeshradiobuttonthenacombinedmeshforthe all the components bonded will be created. If you select the
Incompatiblemesh radio button then individual mesh will be created foreachofthebondedcomponents.
•ClickontheOKbuttonfromthePropertyManagertoapplythecontact.
ContactVisualizationPlotAfter applying various contacts on components of the assembly, you can
reviewthesecontactsbyselectingContactVisualizationPlotbuttonfromtheConnectionsAdvisordrop-downintheRibbon.Thestepstousethisoptionaregivennext.
•ClickontheContactVisualizationPlotbuttonfromtheConnectionsAdvisordrop-down. TheContact Visualization Plot PropertyManager will display as
showninFigure-73.
• Click on theCalculate button from the PropertyManager to display theconnections applied in the assembly. The list of connections will be
displayedintheResultsrollout.•FromSolidWorks2016onwards,youcannowchecktheunconstrainedbodies
in the assembly by using thisPropertyManager. To do so, click on theUnderconstrainedBodiestabfromthePropertyManager.TheoptionswillbedisplayedasshowninFigure-74.
Figure-73.ContactVisualizationPlotPropertyManager
Figure-74.ContactVisualizationPlotPropertyManagerwithUnderconstrainedBodiestab
• Click on theCalculate button to start analyzing the under-constrainedbodies. Once the analysis is done, click one by one on the degree of
freedomavailableforthebodyintheresultsareaofPropertyManagertocheck the constraining of objects. Note that you must have material
propertiesspecifiedtoallthecomponentsbeforeusingthisoption.
•ClickontheOKbuttonfromthePropertyManagertoexitthetool.
SpringThis option is used to connect two components in such a way that they
behave like joined by a spring. The steps to connect two components by
usingtheSpringbuttonaregivennext.
• Click on the Spring button from theConnections Advisor drop-down. TheSpringPropertyManagerwilldisplayasshowninFigure-75.
Figure-75.ConnectorsPropertyManagerwithSpringoption
• Select the desired spring type from theType rollout. There are threetype of springs available in the Type rollout; Compression-Extension,CompressionOnly,andExtensionOnly.
• Select the desired radio button from Flat parallel faces, Concentriccylindricalfaces,andTwolocationsradiobuttons.
•Selecttheentitiesaspertheselectedradiobutton.
•SpecifytheparametersrelatedtospringintheOptionsrollout.Previewofthespringwillbedisplayed;refertoFigure-76.
Figure-76.Previewofspringconnector
•ClickontheOKbuttonfromthePropertyManagertocreatethespringconnection.
PinThisoptionisusedtoconnecttwocylindricalcomponentswiththehelpof
theircircularfaces.Theassembliesthatconsistofmultiplepartscanbe
connected by the pin connector. Examples of assemblies with pins include
laptop flap joined with base, scissors lifts, pliers, and actuators. The
stepstousethisoptionaregivennext.
• Click on the Pin button from the Connections Advisor drop-down. The
ConnectorsPropertyManagerwillbedisplayedwiththeoptionsrelatedtopinconnector;refertoFigure-77.
Figure-77.ConnectorsPropertyManagerwithPinoption
•Selecttheroundfaceofthefirstobjectinassembly.
•Clickinthepinkselectionboxandselecttheroundfaceoftheother
objectintheassembly.
•SelectthedesiredcheckboxesfromtheConnectionTyperollout.
•SpecifytherelevantparametersintheAdvancedOptionrollout.
•SelecttheIncludeMasscheckboxtoincludethemassofthepin.Specifythemassofpinintheeditboxdisplayed.
•ClickontheStrengthDatacheckboxandselectthedesiredmaterialbyselectingtheSelectmaterialbutton.
• Click on the OK button from the PropertyManager to apply the
connection.
BoltThisoptionisusedtosimulatetheboltconnectionbetweentwocomponents
oftheassembly.Ifyouhaveaddedtheboltsintheassemblybyusingthe
Toolboxthenyoucandirectlyconverttheboltintosimulationcomponentby
usingYesoptionfromthedialogboxdisplayedonselectingtheBoltoptionfrom theConnectionsAdvisor drop-down. The steps to use this option aregivennext.
• Click on theBolt option from theConnectionsAdvisor drop-down. If youhave added the bolts in the assembly by using the Toolbox. Then the
Simulationdialog box will be displayed as shown in Figure-78. Click ontheYesbuttontoautomaticallyapplythesimulationconnectionofbolt.
Figure-78.Simulationdialogbox
•IftheboltarenottakenfromtheToolboxoryouselecttheNobuttonfromtheSimulationdialogboxthentheConnectors PropertyManager willdisplaywiththeoptionsrelatedboltconnection;refertoFigure-79.
Figure-79.ConnectorsPropertyManagerwithBoltoption
•SelectthedesiredbuttonfromtheTyperollouttospecifythetypeofbolt.
•Selecttheroundedgeofthebolthead.
•Clickinthenextselectionboxintherolloutandselecttheroundedge
of the nut. Preview of the bolt connector will be displayed; refer to
Figure-80.
Figure-80.Previewofbotconnectorafterselection
•ClickontheTightFitcheckboxtoselectthefacewithwhichtheshankisincontinuouscontact.
• You can specify the material of the bolt by using the Select MaterialbuttonavailableintheMaterialrollout.Thenselectthedesiredmaterialtobeappliedfortheconnections.
•ClickontheStrengthDatacheckboxandspecifytherelatedparametersusingtheoptionsgivenintherolloutdisplayed.
•Youcanapplypreloadontheboltstosimulationtheeffectoftightened
nutsbyusingtheoptionsinthePre-loadrollout.
•Afterspecifyingthedesiredparameters,clickontheOKbuttonfromthe
PropertyManagertoapplytheconnection.
SpotWeldThis option is used to simulate the welding connection between two
componentsataspecificpoints.Theproceduretousethisoptionaregiven
next.
•ClickontheSpotWelds option from theConnectionsAdvisors drop-down.TheConnectorsPropertyManagerwillbedisplayedasshowninFigure-81.
•Selectthefirstfacethatyouwanttobewelded.
•Click in the next selection box in thePropertyManager and select thesecondface.
•Now,clickinthevioletselectionboxandselectthepointatwhichboth
theplatesmeeteachotherorwhereyouwantthespotweldconnectortobe
applied.
Figure-81.ConnectorsPropertyManagerwithSpotWeldsoption
•ClickintheSpotWeldDiametereditboxandspecifythediameterofthespotweldintheunitselectedindrop-down.
• Click on theOK button from the PropertyManager to create the weldconnection.
EdgeWeldThis option is used to simulate the welding connection between two
components at a common edge. The procedure to use this option is given
next.
Figure-82.EdgeWeldConnectorPropertyManager
•ClickontheEdgeWeldbuttonfromtheConnectionsAdvisordrop-down.TheEdgeWeldConnectorPropertyManagerwillbedisplayedasshowninFigure-82.
• Click on the first drop-down list in the Weld Type rollout in
PropertyManagerandselectthetypeoffillet/grooveyouwanttogenerateontheweldingbead.
• Select the first face for welding. Note that you can select only the
shell/surfaceorsheetmetalcomponentstoapplythisconnection.
•Clickinthenextselectionboxandselectthesecondfaceforwelding.
•ClickintheIntersectingEdgesselectionboxandselecttheedgeatwhichtheselectedtwofacesintersect.
•YoucansetthesizeofweldingbyusingtheoptionsintheWeldSizingrollout. You can also switch between American standard and European
standardofweldsizingbyselectingthecorrespondingradiobutton.
LinkThisoptionisusedtosimulatetheconnectionbetweentwocomponentslike
thetwocomponentsarelinkedattheirspecifiedpoints.Theprocedureto
usethisoptionisgivennext.
• Click on the Link button from the Connections Advisor drop-down. The
ConnectorsPropertyManagerwillbedisplayedasshowninFigure-83.•Clickonthedesiredpointoffirstentity.
•Clickinthevioletcoloredselectionboxandselectthesecondpointof
linkonthesecondentity.
•ClickontheOKbuttontocreatethelink.Notethatonspecifyingthe
linkconnector,thedistancebetweenthetwoselectedpointswillremain
thesame.
BearingThisoptionisusedtosimulatetheconnectionbetweentwocomponentslike
the two components are linked to each other with the help of a bearing.
Thisconnectionisgenerallyappliedtoshaftsandhousings.Theprocedure
tousethisoptionisgivennext.
•ClickontheBearingbuttonfromtheConnectionsAdvisor drop-down. TheConnectorsPropertyManagerwillbedisplayedwiththeoptionsrelatedtobearingconnection;refertoFigure-84.
Figure-83.ConnectorsPropertyManagerwithLinkoption
Figure-84.ConnectorsPropertyManagerwithbearingoption
•Selecttheroundfaceoftheshaft.
•ClickinthenextselectionboxintheTyperolloutandselecttheroundfaceofthehousing.
•SpecifythedesiredparametersintheStiffnessrolloutandclickontheOKbuttonfromthePropertyManagertoapplytheconnection.SeeFigure-85.
Figure-85.Previewofbearingconnection
RigidConnectionThisoptionisusedtoapplyrigidconnectionbetweenthetwocomponents.
Theproceduretocreatetherigidconnectionisgivennext.
• Click on theRigidConnection button from theConnectionsAdvisor drop-down. The Connectors PropertyManager will be displayed as shown in
Figure-86.
Figure-86.ConnectorsPropertyManagerwithrigidoption
•Selectthefirstfaceforapplyingrigidconnection.
•Clickinthenextselectionboxandselectthesecondadjoiningface.
• Click on the OK button from the PropertyManager to create the
connection.
After specifying the desired connections for the assembly/component, the
next step is to create and refine mesh for the assembly/component. The
methodstocreatemesharediscussednext.
MESHINGMeshing is the base of FEM. Meshing divides the solid/shell models into
elementsoffinitesizeandshape.Theseelementsarejoinedatsomecommon
pointscallednodes.Thesenodesdefinetheloadtransferfromoneelement
to other element. Meshing is a very crucial step in design analysis. The
automaticmesherinthesoftwaregeneratesameshbasedonaglobalelement
size,tolerance, and local mesh control specifications. Mesh control lets
youspecifydifferentsizesofelementsforcomponents,faces,edges,and
vertices.
The software estimates a global element size for the model taking into
consideration its volume, surface area, and other geometric details. The
size of the generated mesh (number of nodes and elements) depends on the
geometry and dimensions of the model, element size, mesh tolerance, mesh
control,andcontactspecifications.Intheearlystagesofdesignanalysis
where approximate results may suffice, you can specify a larger element
sizeforafastersolution.Foramoreaccuratesolution,asmallerelement
sizemayberequired.
Meshing generates 3D tetrahedral solid elements, 2D triangular shell
elements, and 1D beam elements. A mesh consists of one type of elements
unless the mixed mesh type is specified. Solid elements are naturally
suitable for bulky models. Shell elements are naturally suitable for
modelingthinparts(sheetmetals),andbeamsandtrussesaresuitablefor
modelingstructuralmembers.
Theproceduretocreatethemeshofthesolidisgivennext.
•ClickontheCreateMeshbuttonfromtheRundrop-downintheRibbon.TheMeshPropertyManagerwillbedisplayedasshowninFigure-87.
•Movetheslidertomaketheelementsofmeshfineorcoarse.Ifyoumove
theslidertowardstheright,theelementsofthemeshwillbecomefine.
Ifyoumovetheslidertowardstheleft,themeshwillbecomecoarse.
•SelecttheMeshParameterscheckboxtospecifytheparametersformesh.
•ClickontheCurvaturebasedmeshradiobuttonifyouwanttocreateacurvebasedmesh.
• Click on the Blended curvature-based mesh radio button if you want to
meshtheobjectalongblendedcurvature.Figure-88showsmeshingofaring
bythreemethods.
Figure-87.MeshPropertyManager
Figure-88.Meshtypes
•SelecttheAutomatic transitiontoapplymeshcontrolstosmallfeatures,holes, fillets, and other fine details of your model. Clear Automatic
transitionbeforemeshinglargemodelswithmanysmallfeaturesanddetailstoavoidgeneratinglargenumbersofelements.
•ClickontheAdvancedrollouttoexpandtheadvancedoptionsrelatedtothemesh.
• Jacobian points are used to specify the points on which the distortion
willbecreatedwhileperformingtheanalysis.TosettheJacobianpoints,
click on the drop-down in theAdvanced rollout and select the desirednumberofpoints.
•SelecttheDraftQualityMeshcheckboxtosetthequalityofmeshfor
fast evaluation of the analysis. If you select this check box then 4
corner nodes for solid and 3 corner nodes for each shell element are
created.
•Automatic trails for solidcheckboxisselectedtofindoutandapplytheoptimummeshsizeautomatically.Notethattheratiobywhichtheglobal
elementsizeandtolerancearereducedforeachtrialis0.8.Onselectingthis check box, the Number of trials spinner is displayed. Using this
spinner,youcanspecifythemaximumnumberoftrialsforre-meshing.
• If your part fails while meshing at some portions, then select the
Remeshfailedpartswith incompatiblemeshcheckboxtocreateincompatiblemeshattheportionsthatfailed.
•Ifyoudonotwanttoactuallymeshbutwanttosavethesettingsthen
selecttheSavesettingswithoutmeshingcheckbox.
• To run the analysis directly after creation of mesh, select the Run(solve)theanalysischeckbox.
Figure-89showsthemeshingofamodelwiththeloadsandfixturesapplied.
Figure-89.Previewofmeshwithloadsapplied
RUNNINGANALYSISAfter we have applied all the parameters related to analysis and we have
createdthemesh,thenextstepistoruntheanalysis.Thestepstorun
theanalysisaregivennext.
•ClickontheRunbuttonfromtheRibbon.Theanalyzingwillstartandtheresultwillbedisplayed;refertoFigure-90.
•Afterweruntheanalysis,thenextstepistointerprettheresultsof
theanalysis.Tointerprettheresultsforvariouspurposes,thetoolsare
availableintheResultAdvisorsdrop-downwhichisdiscussednext.Figure-90.Previewofsimulationresult
RESULTSADVISORThetoolsinthisdrop-downareavailableonlyafteryousuccessfullyrun
the desired type of analysis. The tools that get available after running
staticanalysisaregivennext.
•ResultsAdvisor
•ModelOnly(NoResults)
•NewPlotmenu
•ListStress,DisplacementandStrain
•ListResultForce
•ListContactForce
•ListPin\Bolt\BearingForce
Thetoolsabovearediscussednext.
ResultsAdvisorThis tool is used to display the result page of the Simulation Advisor;refertoFigure-91.ThestepstousetheoptionsinthispageofSimulation
Advisoraregivennext.
• Click on the Play button from the Simulation Advisor to plat the
simulationoftheappliedanalysis.Notethatthelimitsofdeflectionare
displayed in the Simulation Advisor. For example, in Figure-91, the
maximumdeflectionis2.29361e-005m.
•Afteryouhavecheckedthesimulation,youneedtochangetheparameters
ofmodeltogetthedesiredresults.Forexample,youwanttochangethe
materialtoincreasethestiffnessofthemodel.Toperformthesechanges,
weareprovidedwiththethreelinkbuttonsintheSimulationAdvisor.
• Click on the desired link button from the first three link buttons to
changetheparameters.Wewilldiscusstheseoptionslaterinthebook.
Figure-91.ResultspageSimulationAdvisor
ModelOnly(NoResults)This tool is used to display the model without displaying any result of
analysis.Useofthistoolsisverysimple,justclickonthetoolandthe
analysisresultwillhidautomatically.
NewPlotThe options in this cascading menu are used to generate new plots for
variousparametersonthebasisofperformedanalysis.IncaseofaStatic
analysis,youcangettheoptionsasshowninFigure-92.
Figure-92.OptionsinNewPlotcascadingmenu
The Stress, Strain and Displacement plots are added in the results
automatically.TheproceduretoaddFactorofSafetywillbediscussedin
next chapter. The procedures to add Design Insight, and Results Equation
plotsaregivennext.
DesignInsight• Click on the desired option from the menu. The respective
PropertyManagerwilldisplay;refertoFigure-93forDesignInsight.
Figure-93.DesignInsightPropertyManager
•SpecifythedesiredsettingsinSettingstabofthePropertyManagerandclick on the OK button display the desired type of analysis result;
refertoFigure-94.Notethatthelinkforselectedanalysisresultwill
beaddedintheResultsnodeintheleftarea.
Figure-94.Previewfordesigninsight
ResultsEquation•ClickontheResultsAdvisor->NewPlot->Results Equation option fromtheRibbon. TheResults Equation Plot PropertyManager will be displayedalongwiththeEditEquationdialogbox;refertoFigure-95.
Figure-95.ResultsEquationPlotPropertyManagerwithEditEquationdialogbox
• Select theNodeValues radio button or theElementValues radio buttonfromthedialogboxtomakeequationsfornodesorelementsinthemodel
respectively.
• Specify desired formula in the edit box like, “EPSX: X NormalStrain”+”EPSY:YNormalStrain”+”EPSZ:ZNormalStrain”tochecktriaxialstrainoneachnodeorelementintheresult.Notethatwhenyoutypea
mathematical operator or click in the empty edit box then a flyout is
displayed with equation parameters; refer to Figure-96. You can select
theseparametersforcreatingtheequation.
Figure-96.Flyoutwithequationparameters
•Aftercreatingequation,clickontheOKbuttonfromthedialogbox.
•EnterthedesirednameofplotintheLegendtitletexteditboxofEquationPlotOptionsrolloutofthePropertyManager.
•SelectthedesiredunitsystemfromtheUnitsdrop-downintherollout.
• Set the other parameters as required and then click on theOK button
fromthePropertyManager.Thenewplotwillbecreated;refertoFigure-97.NotethatthenewplotwillbeaddedintheResultsnodeattherightofthedialogbox.
Figure-97.Triaxialstrainplot
ListStress,DisplacementandStrainThistoolisusedtodisplaythevaluesofstress,displacementandstrain
at node intersecting with the selected plane. The procedure to use this
optionisgivennext.
• Select the plane by using which you want to check values of stress,
displacementandstrainattheintersectingnodes.
• Click on the List Stress, Displacement and Strain tool from the ResultsAdvisor drop-down. TheListResults PropertyManager will be displayed asshowninFigure-98.
• Select the desired radio button from theQuantity rollout. The optionsrelatedtotheselectedradiobuttonwillbedisplayedintheComponentrollout.Selectthedesiredcomponentofstress/displacement/strainfrom
thefirstdrop-downintherollout.
•ClickontheAdvancedOptionstoexpandtherollout.Theadvancedoptionsrelatedtotheselectedradiobuttonwillbedisplayed.RefertoFigure-
99.
Figure-98.ListResultsPropertyManager
Figure-99.ListResultsPropertyManagerwithexpandedAdvancedOptionsrollout
• Select the desired parameters from theAdvanced Options rollout to setthelimitsofdisplayedresult.
•ClickontheOKbuttonfromthePropertyManager.TheListResultsdialogboxwillbedisplayed;refertoFigure-100.
•ClickontheSavebuttontosavetheresultsinaCSVexcelfile.ClickontheClosebuttontoclosethedialogbox.
Figure-100.ListResultsdialogbox
ResultForceThis tool is used to display the reaction forces resulting due to the
appliedload.Thestepstousethistoolaregivennext.
• Click on theResult Force tool from theResults Advisor drop-down. The
ResultForcePropertyManagerwillbedisplayedasshowninFigure-101.
•SelectthedesiredradiobuttonfromthePropertyManager.•Clickintheblueselectionboxandselecttheface/edge/pointatwhich
youwanttocheckthereactionforces.
• Select the desired unit system from the Unit drop-down in the
PropertyManager.
• Click on the Update button from the PropertyManager to display the
reaction forces. The box containing values of reaction forces will be
displayedwiththemodel;refertoFigure-102.
Figure-101.ResultForcePropertyManager
Figure-102.Previewofresultforce
•ClickontheOKbuttonfromthePropertyManagertoexitthetool.
IfyouhaveappliedcontactforcesorPin/Bolt/Bearingforces,thenclick
ontherespectivetoolfromtheResultsAdvisordrop-down.Theresultwillbedisplayedinthesamewayasdiscussedearlier.
We will learn about more options related to results while performing the
analysesinsubsequentchapters.
SELF-ASSESSMENT
Q.1Wecanperformstaticanalysisonobjectswithoutapplyingmaterialto
object.(T/F)
Q2.Ifyoudonotapplyfixturesthentheobjectwillbefreetomovein
thedirectionofforcesappliedandnostressorstrainwillbeinducedin
it.(T/F)
Q3.UsingtheFixedGeometryfixturetype,youcanfixtheface,edgeor
pointoftheobject.(T/F)
Q4.TheFixedHingetoolisusedtofixafaceinsuchawaythatitcanslide/rollinitsplanebutcannotmoveperpendiculartotheplane.
Q5.Aliveexampleofelasticsupportfixturecanbeanobjectplacedon
wood,rubberoranyspringbase.(T/F)
Q6. Which of the following fixture option makes the object move in
specifieddirectionandrestrictsmotioninotherdirections?
a.UseReferenceGeometry
b.CyclicSymmetry
c.ElasticSupport
d.Roller/Slider
Q7.WhichofthefollowingrolloutinForce/TorquePropertyManagerisusedtodefineequationfornon-uniformforcedistribution?
a.Force/Torque
b.NonuniformDistribution
c.SymbolSettings
d.Selection
Q8.…………….isproductofforceanddistance.
Q9.…………..isforceappliedperunitarea.
Q10. …………. force is a force which causes the rotating objects to move
outwardoftheircircularpath.
PreparingModelforAnalysis
Chapter3
TopicsCovered
Themajortopicscoveredinthischapterare:
•CreatingReferenceGeometry
•SimplifyingModelforAnalysis
•ExtrudeandRevolveTool
•SplittingFacesandBody
•GeneratingMidSurface
•AddingandSubtractingBodies
•ImportingParts
INTRODUCTIONNoPal!Youcannotrunanalysisdirectlyonamodelwhichhasfilletsand
other feature. The features like fillet, chamfer, holes (which are not
playingroleinanalysis)etc.increasethesolutiontimeanderrorofthe
analysis. So, we need to de-feature the model before running analysis in
SolidWorksSimulation.ThereisaseparateCommandManagerinSolidWorksto simplify model called Analysis Preparation CommandManager; refer to
Figure-1.
Figure-1.AnalysisPreparationCommandManager
Youcanperformmanyothertasklikefindingmid-surface,splittingfaces,
creatingreferencefeaturesetc.usingthetoolsinthisCommandManager.ThemostcommonlyusedtoolsinthisCommandManageraregivennext.
REFERENCEGEOMETRYThere are various types of reference geometries that can be created in
SolidWorks. All the tools to create these reference geometries are
availableintheReferenceGeometrydrop-down;refertoFigure-2.Thetoolsavailableinthedrop-downare:
•Plane
•Axis
•CoordinateSystem
•Point
•CenterofMass
•MateReference
Figure-2.Referencedrop-down
Thesetoolsarediscussednext.
PlaneThePlane tool is used to create reference planes. By default there arethreeplanesavailableinSolidWorks:Front,Top,andRight.Tocreatemoreplanesfollowthestepsgivennext.
•ClickonthePlanetoolfromtheReferenceGeometrydrop-down.ThePlanePropertyManagerwilldisplayasshowninFigure-3.
Figure-3.PlanePropertyManager
•Youcanselectmaximumthreereferencestocreateaplane.Youcanselect
plane/face, edge/axis/curve, or vertex/point. The ways in which you can
createplanesbyusingthesereferencesarediscussednext.
Creatingplaneatadistancefromplane/face•Tocreateaplaneatadistancefromaplane/face,selecttheplane/face.
TheupdatedPlanePropertyManagerwilldisplayasshowninFigure-4.•Specifythedesireddistanceinthespinner.
•ClickontheOKbuttontocreatetheplane.
Figure-4.UpdatedPlanePropertyManager
Creatingplaneatanangletoplane/face•ActivatethePlanePropertyManagerandselectaplane/facetowhichyouwanttospecifytheangle.
•ClickontheAtAnglebuttontospecifytheangle.
•ClickintheSecondReferenceboxandselecttheedgeoraxistowhichyouwanttomaketheplanecoincidentorselectthetwoplanarpointthrough
whichyouwanttheplanetopass.Figure-5showstheplanecreatebyboth
themethodsdiscussed.
Figure-5.Planecreationatangle
Creatingplanepassingthroughpoints• Activate the Plane PropertyManager and one by one click three pointsthroughwhichyouwanttheplanetopassthrough.Figure-6showstheplane
passingthroughthreepoints.
Figure-6.Planepassingthroughthreepoints
PlaneParalleltoScreenThis option is a new feature of SolidWorks 2016. The procedure to create
planeparalleltoscreenisgivennext.
•Right-clickonanyface,edge,orvertexofthemodel.Ashortcutmenu
willbedisplayed;refertoFigure-7.
Figure-7.Shortcutmenuonrightclickingonaface
•ClickontheCreatePlaneParalleltoScreenoptionfromtheshortcutmenu.Aplaneparalleltoscreenwillbecreated;refertoFigure-8.
Figure-8.Planeparalleltoscreen
AxisThe Axis tool is used to create reference axes. An axis is useful in
creating revolve features or to create planes at angle. To procedure to
createaxisbyusingtheAxistoolisgivennext.
• Click on the Axis tool from the Reference drop-down. The AxisPropertyManagerwilldisplayasshowninFigure-9.
•SelectthedesiredbuttonfromthePropertyManager.ThebuttonsinthisPropertyManagerareexplainednext.
Figure-9.AxisPropertyManager
OneLine/Edge/AxisSelectthisbuttonifyouwanttocreateanaxiscoincidenttotheselected
line/edge/axis. After selecting this button, click on the line/edge/axis.
Theaxiswillbecreatedcoincidenttotheselectedline/edge/axis;refer
toFigure-10.
Figure-10.Axiscreatedonedge
TwoPlanes
SelecttheTwoPlanesbuttonifyouwanttocreateaxisattheintersectionofthetwoselectedplanes/faces.Afterselectingthisbutton,clickonthe
two intersecting. The axis will be created at the intersection; refer to
Figure-11.
Figure-11.Axisatintersectionofplanes
TwoPoints/VerticesSelect the Two Points/Vertices button if you want to create axis passingthroughtheselectedtwopoints/vertices;refertoFigure-12.
Figure-12.Axispassingthroughtwopointsorvertices
Cylindrical/ConicalFaceSelect theCylindrical/Conical Face button and select a cylindrical/conicalface. An axis passing through center of cylindrical/conical face will be
created;refertoFigure-13.
Figure-13.Axisthroughcylinderandconical
PointandFace/PlaneSelectthePointandFace/Planebuttonifyouwanttocreateanaxispassingthroughtheselectedpointandperpendiculartotheselectedface/plane.
CoordinateSystemTheCoordinateSystemtoolisusedtocreatereferencecoordinatesystem.
Thestepstocreatecoordinatesystemareexplainednext.
• Click on theCoordinate System tool from theReference drop-down. TheCoordinateSystemPropertyManagerwilldisplayasshowninFigure-14.
Figure-14.CoordinateSystemPropertyManager
•Clickonthepointwhereyouwanttoplacethecoordinatesystem.
•Clickintheboxforwhichyouwanttospecifydirectionreferenceand
select the reference like plane, axis and so on. Figure-15 shows a
coordinatesystemcreatedontheface.
Figure-15.Coordinatesystemcreation
PointThePointtoolisusedtocreatereferencepointsonthemodel.Thestepstocreatepointsaregivennext.
• Click on the Point tool from the Reference drop-down. The PointPropertyManagerwilldisplayasshowninFigure-16.
• Select the desired button to specify the type of point you want to
create.Inthiscase,wehaveselectedCenterofFacebutton.• Select the reference (face of the model in this case). Preview of the
pointwilldisplay;refertoFigure-17.
Figure-16.PointPropertyManager
Figure-17.Previewofpoint
•ClickontheOKbuttontocreatethepoint.
Youcancreatearrayofpointsalongacurvebyselecting button.
CenterofMassTheCenterofMasstoolisusedtodisplaythecenterofmassofthemodel.The coordinates of center of mass are generally required in some
calculationsrelatedtoinertiaoftheobjects.Identificationofcenterof
massisalsohelpfulincheckingthestabilityofobjectinconstraintfree
environment.Todisplaythecenterofmass,clickontheCenterofMasstoolfrom theReference drop-down and the center of mass will display in theviewport;refertoFigure-18.
Figure-18.Centerofmassofcylinder
SIMPLIFY
TheSimplifytoolisusedtoremovethefeaturesthatareofnoimportanceinthecurrentanalysis.Theproceduretousethistoolisgivennext.
•ClickontheSimplifytoolfromtheAnalysisPreparationCommandManager.TheSimplifytaskpanewillbedisplayedattherightintheapplicationwindow;refertoFigure-19.
Figure-19.Simplifytaskpane
•ClickintheFeaturesdrop-downoftaskpaneandselectthecheckboxesoffeaturesthatyouwanttobesimplified.
• Specify the desired simplification factor in the Simplification factorspinner and select the radio button below it to set the simplification
factortype.
• Click on the Find Now button to search for the features that can besimplifiedbasedonyourinputs.Thefeaturesthatcanbesimplifiedor
saysuppressedaredisplayedintheResultsareaofthetaskpane.•Selectthefeaturesthatdonothaveanyeffectonyouranalysiswhile
holdingCTRLkey;refertoFigure-20.
Figure-20.Featurestobesimplified
•Specifythenameofnewconfigurationofpart/assemblytobecreatedwith
suppressedfeaturesintheNameeditboxatthebottomofthetaskpane.MakesuretheCreatederivedconfigurationcheckboxisselected.
• Click on the Suppress button at the bottom in the task pane. A new
configurationwith suppressedfeatures will be created on which you can
performtheanalysis;refertoFigure-21.
Figure-21.Simplifyingmodel
EXTRUDEDBOSS/BASETOOLExtrudedBoss/Basetoolisusedtocreateasolidvolumebyaddingheighttotheselectedsketch.Inotherwords,thistooladdsmaterial(byusingthe
boundaries of sketch) in the direction perpendicular to the plane of
sketch.InthetermBoss/Base;theBasedenotesthefirstfeatureandBoss
denotes the feature created on any other feature. The steps to create
extrudedfeatureisgivennext.
• Click on the Extruded Boss/Base tool from the Ribbon. The ExtrudePropertyManagerwilldisplay;refertoFigure-22.
Figure-22.ExtrudePropertyManager
•Selectaplanefromtheplanesdisplayedintheviewport.Thesketching
environmentwilldisplaywiththesketchtoolsactivated.
•CreateaclosedsketchandthenclickontheExitSketchbuttonfromtheviewportasshowninFigure-23.YoucanalsoselecttheExitSketchbuttonfromtheRibbon.TheBoss-ExtrudePropertyManagerwilldisplayasshowninFigure-24.
Figure-23.Sketchenvironmentofextrude
Figure-24.Boss-ExtrudePropertyManager
•ClickontheStartingreferencedrop-downandselectthedesiredoption.
Therearefouroptionsinthisdrop-down;SketchPlane,Surface/Face/Plane,Vertex, andOffset. The Sketch Plane is selected by default. Select thisoptionifyouwanttheextrusiontostartfromsketchingplane.Selectthe
Surface/Face/Plane option to start the extrusion from the selected
surface/face/plane. Select the Vertex option to start extrusion from
selectedvertex.SelecttheOffsetoptionifyouwanttostartatspecifieddistancefromthesketchingplane;refertoFigure-25.
Figure-25.Previewofoffsetoption
•ClickintheLimitingreferencetypedrop-downandselectthereferencefor
endofextrusion.
Therearesixoptionsinthedrop-down;Blind,UpToVertex,UpToSurface,OffsetFromSurface,UpToBody,andMidPlane.IfyouhaveselectedBlindorMidPlane option, then you need to specify the distance value in theHeight of extrusion spinner. If you have selected any of the other optionthen select the respective reference from the viewport. Figure-26 shows
previewofextrusionbyusingtheMidPlaneoption.NotethatifMidPlaneoptionisselectedthentheDirection2rolloutwillnotdisplay.
Figure-26.Mid-Planeextrusion
•ClickintheDirectionofextrusionselectionboxandselectthereferenceif you do not want to extrude perpendicular to the sketching plane and
wanttoextrudealongselectedaxis/plane
• Click in the edit box for extrusion height and enter the desired
extrusionheightoryoucansetthevaluebyusingspinner.
• Click on theDraftOn/Off button to apply draft angle on the verticalfacesofthemodel.Onselectingthisbutton,1°draftwillbeappliedbydefaulttakingthesketchingplaneasreference.SelecttheDraftoutwardcheck box to apply draft angle outwards on the vertical faces of
extrusion.SpecifythedraftangleintheDraftAnglespinner.
The parameters you specified above can also be applied to the opposite
direction.Toapplytheseparameters,selecttheDirection2checkbox.Theparametersfortheoppositedirectionwilldisplay.
• Select theThin Feature check box to create the thin walled extrusion.EnterthethicknessintheThicknesseditboxoftheThinFeaturerollout.Figure-27showsathinfeaturedextrusion.Notethatifopensketchisselectedforextrudethenthisoptiongetsselectedautomatically.
Figure-27.ThinFeatureextrusion
•Ifyouwanttoclosethestartandendfaceoftheextrusionthenselect
theCapEndscheckbox;refertoFigure-28.
Figure-28.Extrusionwithcapends
•Onceyouhavefinishedcreatingthefeature,clickontheDetailedPreviewbuttonfromthePropertyManagertoverifythefeature;refertoFigure-29.
Figure-29.DetailedPreviewbutton
• Select the Highlight new or modified faces check box if you want to
highlightthenew/modifiedfacesonly.Similarly,youcanselecttheShowonly new ormodifiedbodiescheckboxifyouwanttodisplayonlynewormodifiedobjects.
InSolidWorks2017,youcanalsoactivatetheExtrudeBoss/BasetoolbyALTkey. To do so, press the ALT key from keyboard and click on the shaded
sketch section in the Sketching environment. The Extrude button will bedisplayed; refer to Figure-30. Click on the Extrude button to display
Extrude PropertyManager. Rest of the procedure is same as discussed
earlier.
Figure-30.Alternatemethodforextrude
REVOLVEDBOSS/BASETOOLRevolved Boss/Base tool is used to create a solid volume by revolving asketchaboutselectedaxis.Inotherwords,ifyourevolveasketchabout
anaxisthenthevolumethatissweptbyrevolvedsketchboundaryiscalled
revolvedboss/basefeature.Thestepstocreaterevolvedboss/basefeature
aregivennext.
• Click on the Revolved Boss/Base tool. If you have not selected any
existing sketch, then theRevolve PropertyManager displays as shown inFigure-31.
Figure-31.RevolvePropertyManager
•Selectaplaneifyouwanttocreateanewsketchorselectanalready
createdsketch.Inourcase,weareselectinganalreadycreatedsketch.
• Select the region of the sketch that you want to revolve if you have
multiple loops in sketch; refer to Figure-32. The updated RevolveProperyManagerwilldisplayasshowninFigure-33.
Figure-32.Regionselectedforrevolve
Figure-33.UpdatedRevolvePropertyManager
•ClickintheAxis ofRevolutionselectionboxtoselecttheaxis.Selecttheedge,line,orcenterlineaboutwhichyouwanttorevolvethesketch.
Previewoftherevolvefeaturewilldisplay;refertoFigure-34.
Figure-34.Previewofrevolvefeature
•ClickontheRevolveTypedrop-downandspecifytherevolutionlimitingreference. The options in this drop-down are same as discussed for
ExtrudedBoss/Basetool.
• If you have selected Blind option in the Revolve Type drop-down then
specifythedegreesofrevolutionbyusingtheAnglespinner.
•ClickontheDirection2 check box to revolve in the direction oppositethe earlier on. The options in the Direction 2 rollout are same as
discussedearlier.
•YoucanalsocreatethinfeaturebyselectingtheThinFeaturecheckbox.Notethatifyouselectanopensketchthenthisoptionisautomaticallyselected.
•ClickintheSelectedContoursboxtoaddmoresketchesforrevolutionandselectthesketchesyouwanttorevolve.
Figure-35showsasketch,axisofrevolution,andresultingrevolvefeature
preview.
Figure-35.Revolvedfeature
EXTRUDEDCUTTheExtrudeCut tool is used to remove material by extruding the sketch.Thestepstousethistoolaregivennext.
• Click on the Extruded Cut tool. The Cut-Extrude PropertyManager willdisplay.
•Selectthefacefromwhichyouwanttostartremovingthematerial.The
sketchenvironmentwillactivate.
•Clickthesketchusingwhichyouwanttoremovethematerial.
• Click on the Exit Sketch button from the Ribbon. The preview of cut
featurewilldisplay;refertoFigure-36.
Figure-36.Previewofextrudecutfeature
• Specify the depth of material removal and other parameters in the
PropertyManagerasdiscussedforExtrudeBoss/BasetoolandthenclickontheOKbutton.
MIRRORTheMirror tool is used to create mirror copy of the features in the
Modelingenvironment.Theproceduretocreatemirrorisgivennext.
•Selectallthefeaturesthatyouwanttomirror.
•ClickontheMirrortoolfromtheAnalysisPreparationCommandManagerin the Ribbon. The Mirror PropertyManager will display as shown in
Figure-37.
• Select the plane or face about which you want to mirror the features.
Previewofthemirrorwillbedisplayed;refertoFigure-38.
•ClickontheOKbuttonfromthePropertyManagertocreatethefeature.Figure-37.MirrorPropertyManager
Figure-38.Previewofmirror
Ifyouwanttomirroracompletebodywithrespecttomirrorplaneasin
theabovefigure,thenfollowthestepsgivennext.
•ClickontheMirrortool.TheMirrorPropertyManagerwilldisplay.
• Expand the Bodies to Mirror rollout and click on the bodies in the
viewportthatyouwanttomirror.
•ClickintheMirrorFace/PlaneboxintheMirrorFace/PlanerolloutoftheProperyManager and select the mirror plane. Preview of mirror will
display; refer to Figure-39. Make sure that you clear theMerge solidscheckboxbeforecreatingthemirrorcopy.
•ClickontheOKbuttontocreatethemirrorcopy.
Figure-39.Previewofbodymirror
SPLITLINETOOLInsomeofthecases,youneedtoapplyloadorconstraintataconfined
areaoffaceratherthenthefullarea.Inthatyoucase,youneedtosplit
theface.Thestepsgivennextexplaintheprocedureofsplitting.
• Click on the Split Line tool from the Ribbon. The Split LinePropertyManagerwillbedisplayedasshowninFigure-40.
Figure-40.SplitLinePropertyManager
•Bydefault,Projectionradiobutton is selected and you aresupposedtoselectasketchfordividingtheface.Figure-41showsapartthatneedto
bedividedfrommid.
Figure-41.Parttobesplitted
•AlinesketchisdrawnatthecenterofthemoldpartonRight-planeso
thatitcandividethepartintotwopieces;refertoFigure-42.
Notethattodrawthesketch,youneedtocanceltheSplitLinetool,selectthe Sketch CommandManager from the Ribbon and after you draw the
sketch,youneedtoselecttheSplitLinetoolagain.
Figure-42.Sketchedlinedrawnatthecenter
•Selectthelinesketch,itwillbedisplayedinthefirstselectionbox
intheSplitLinePropertyManager.•Clickinthenextselectionbox.Youwillbeaskedtoselectthefacesto
besplitup.
• Select all the faces of the part that you want to split by using the
projectionofsketch;refertoFigure-43.
• Select the OK button from the PropertyManager, the part will be
displayedasshowninFigure-44.
Figure-43.Facesselected
Figure-44.Partaftersplitting
• You can also split this part by using the Silhouette radio button. Butthat will be based on the mold analysis which is out of scope of this
book. In the same way, you can split the part by using the Intersectionradiobutton;refertoFigure-45.
Figure-45.Splittingbyintersection
MIDSURFACETheMid Surface tool is used to create a surface at the mid of selectedfacesofthepart.Youmayaskwhatisthebenefitofthisforsimulation.
Mostofthetimewhenyouremoveextrafeaturesfromyourmodel,themodel
isaplanepieceofmetalwithdifferentthicknessesatdifferentplaces.
Whenyouperformanalysisonasolid,thenumberofelementsduringmeshing
areveryhighduetostackingofelementsalongZdirectionapartfromX
and Y directions. If you create mid surface of solid and apply thickness
usingtheShellManagerthennumberofelementsarereduced.Inturn,thetime taken by analysis is reduced. When you apply thickness using ShellManager then 3D model of part remains in surface but while solving
analysis equation, value of thickness is applied in equations
automatically.TheproceduretocreateMidsurfaceisgivennext.
• Click on the Mid Surface tool from the Analysis PreparationCommandManager. The MidSurface PropertyManager will be displayed;
refertoFigure-46.Also,youwillbeaskedtoselectthefirstfacefor
creatingmid-surface.
Figure-46.MidSurfacePropertyManager
• Select the first face of the model. You will be asked to select the
secondfaceofthemodelincurrentset.
•Selectthesecondface,asetwillbecreatedintheFacepairsselectionbox;refertoFigure-47.
Figure-47.Faceselectionformidsurface
•AfterselectiontheFace1andFace2selectionboxeswillbecomeemptypromptingyoutoselectthenextset.
•Ifyouwanttofindthefacepairsautomaticallyformidsurfacethendo
not select any face manually. In the Recognition Threshold drop-down,
selectthedesiredoperatorandthenspecifythevalueofthresholdinthe
edit box next to it. Click on the Find Face Pairs button from the
PropertyManager.Mostofthefaceswillgetselectedautomatically;refertoFigure-48.
Figure-48.Facepairsselectedautomatically
•Selecttherestofthefaceasdiscussedearlierifrequired.
• Set the position of the mid-surface using the Position spinner. If thepositionvalueis50%thenmidsurfacewillbecreatedatthecenterofthefacepairs.
•ClickontheOKbuttonfromthePropertyManagertocreatethesurface.Hiderestofthefeaturetocheckthemid-surface;refertoFigure-49.
Figure-49.Solidtomidsurface
SPLITTOOL
TheSplittoolisusedtocreatemultiplebodiesofasolidbodybyusingatrimmingtool.Theproceduretousethistoolisgivennext.
•ClickontheSplittoolfromtheAnalysisPreparationCommandManagerintheRibbon.TheSplitPropertyManagerwillbedisplayed;refertoFigure-50.
Figure-50.SplitPropertyManager
• Select the plane/surface/sketch to be used as trimming tool. Note that
theplane/surfaceshouldintersectthepart.
•ClickontheCutPart tool from thePropertyManager. The part will beseparatedintomultiplebodies.
•SelectthecheckboxesfromtheResultingBodiesrollouttocreatesplits.
•SelecttheConsumecutbodiescheckboxtoconsumethebodyselectedintheResultingBodiesrollout.
• Select the Propagate visual properties check box to apply the same
propertiestothesplitbodieswhichwereappliedtothemainbody.
•ClickontheOKbuttonfromthePropertyManager.
COMBINETOOLTheCombine tool is used to add/subtract two or more solid bodies. Theproceduretousethistoolisgivennext.
• Click on the Combine tool from the Analysis PreparationCommandManager.TheCombinePropertyManagerwillbedisplayed;refertoFigure-51.
Figure-51.CombinePropertyManager
AddingSolidBodies•SelecttheAddradiobuttonfromtheOperationTyperolloutandselectallthebodiesthatyouwanttobecombined.
•ClickontheOKbuttonfromthePropertyManagertocombinebodies.
SubtractingSolidBodies• Select the Subtract radio button from the Operation Type rollout and
selectthemainbodyfromwhichyouwanttosubtractothersolidbodies.
Youwillbeaskedtoselectthebodiestobesubtracted.
•Selectthebodiesthatyouwanttobesubtractedfromthemainbody.
•ClickontheOKbuttonfromthePropertyManager.
INTERSECTTOOLThe Intersect tool is used to intersect solids, surfaces, or planes to
modify existing geometry or create a new geometry of intersection
boundaries.Theproceduretousethistoolisgivennext.
•ClickontheIntersecttoolfromtheAnalysisPreparationCommandManager.TheIntersectPropertyManager will be displayed; refer to Figure-52. Youwillbeaskedtoselectthebodieswhichareintersecting.
Figure-52.IntersectPropertyManager
• Select the intersecting solids, surfaces, or planes which are forming
closedsection.
• Select the desired radio button from the PropertyManager to create
desiredregionsafterintersection.
•Clickonthe IntersectbuttonfromthePropertyManager. Various regionsof the solid will be displayed in the drawing area as well as in the
RegiontoExcluderollout;refertoFigure-53.
Figure-53.Regionscreatedfromsolid
• Select the check box from the Region to Exclude rollout to exclude
selectedregion.
•Ifyouwanttomergeallthecreatedregionstoformonebodythenselect
theMergeresultcheckboxfromOptionsrolloutofthePropertyManager.
• Similarly, select the Consume surfaces check box to delete the
interestingsurfacesaftercreatingtheregions.
• Click on the OK button from the PropertyManager to create the
body/regions.
MOVE/COPYBODIESTOOLTheMove/Copy Bodies tool is used to move or copy selected bodies. Theproceduretousethistoolisgivennext.
• Click on the Move/Copy Bodies tool from the Analysis PreparationCommandManager.TheMove/CopyBodyPropertyManagerwillbedisplayedasshowninFigure-54.
Figure-54.Move/CopyBodyPropertyManager
•Selectthebody/bodiestobemovedorcopied.Atriadforrotating/moving
the part will be displayed. Drag or rotate the triad using respective
handlestomove/rotate.
• To move the body/bodies by desired distance, click in the TranslateReference selection box from the Translate rollout and select a
point/edge/coordinatesystemfordirectionreference.Specifythedesired
distancevaluesintherespectiveeditboxesofTranslaterollout.
• Expand theRotate rollout in the PropertyManager and set the desiredrotationvaluesasrequired.
•ClickontheOKbuttonfromthePropertyManagertoapplythechanges.
Similarly,youcanusetheDelete/KeepBodytool.Ifyoufindanydoubtinworkingwiththistoolpleaseemailme.
OthertoolsofSolidWorksarediscussedinourbook:SolidWorks2017BlackBook.
IMPORTINGPART•ClickontheOpenbuttonfromtheQuickAccessToolbar or press CTRL+O
fromthekeyboard.TheOpendialogboxwillbedisplayed.
•Double-clickonthedesiredfilethatyouwanttoopen.MakesuretheAllFilesordesiredfiletypeisselectedintheFileType drop-down in thedialog box; refer to Figure-55. The respective SOLIDWORKS Converterdialogboxwillbedisplayed;refertoFigure-56.
Figure-55.FileTypedrop-down
Figure-56.SOLIDWORKSConverterdialogbox
• Select the Import geometry directly radio button and select the desiredradiobuttontoimportthegeometriesofselectedfile.Ifyouselectthe
BREP radio button the model is imported as solid with Boundary
Representation data. If you select the Knitting radio button then the
modelwillbeimportedassurfacesknittedtogetherandifyoualsoselect
theTry forming solidmodel(s)checkboxthensystemwillformasolidifsurfaceformclosedboundaries.IfyouselecttheDonotknitthesurfaces
willbeimportedinSolidWorks.
•IfyouwanttoSolidWorkstorecogniseasmanyfeaturesaspossiblein
theimportedmodelthenselecttheAnalyzethemodelcompletelyradiobuttonfromthedialogbox.
•Selectthedesiredcheckboxesfromthedialogboxtoimportrespective
parametersofthemodel.
•ClickontheOKbuttonfromthedialogbox.IfyouselectedtheAnalyze
themodelcompletelyradiobuttonearlierthenaninformationboxwillbe
displayed; refer to Figure-57. Click on theBody button and select thedesiredcheckboxes.TheSOLIDWORKSdialogboxwillbedisplayedasshowninFigure-58.
Figure-57.Informationbox
Figure-58.SOLIDWORKSdialogbox
Figure-59.ImportDiagnosticsPropertyManager
•ClickontheYesbuttonfromthedialogboxtostartimportdiagnosticwhich help in finding any inconsistency of imported model. The ImportDiagnosticsPropertyManagerwillbedisplayed;refertoFigure-59.
• Click on the Attempt to Heal All button to heal the faces/gaps. The
faces/gaps which are not able to heal automatically should either be
deletedorremodelled.
•ClickontheOKbuttonfromthePropertyManagertosolveproblemsofimportedparts.
StaticAnalysis
Chapter4
TopicsCovered
Themajortopicscoveredinthischapterare:
•StartingStaticAnalysis.
•ApplyingMaterial.
•DefiningFixtures
•Applyingloads
•DefiningConnections
•SimulatingAnalysis.
•Interpretingresults
LINEARSTATICANALYSISLinear static analysis is performed to calculate stresses, displacements,
strains,forces, anderror estimatesunder variousloading conditions. On
applying the loads, the body gets deformed and the loads are transmitted
throughoutthebody.Thedeformationandothereffectsofbodyarestudied
underthisanalysis.
AssumptionsSomeassumptionsaremadeinthistypeofanalysis,like:
1.Theloadsapplieddoesnotvarywithtime.
2.Allloadsareappliedslowlyandgraduallyuntiltheyreachtothefull
magnitude and after reaching the full magnitude, the loads remain
constant.Thereby,neglectingimpact,inertial,anddampingforces.
3.ThematerialsappliedtothecomponentssatisfytheHooke’slaw.
4.Thechangeinstiffnessduetoloadingisneglected.
5.Boundaryconditionsdonotvaryduringtheapplicationofloads.Loads
mustbeconstantinmagnitude,direction,anddistribution.
GeometryAssumptions1.ThepartmodelmustrepresenttherequiredCADgeometry.
2.Onlytheinternalfilletsintheareaofinterestwillbeincludedin
thestudy.
3.Shellsarecreatedwhenthicknessofthepartissmallincomparisonto
itswidthandlength.
4.Thicknessoftheshellisassumedtobeconstant.
5. If the dimensions of a particular part are not critical and do not
affecttheanalysisresults,someapproximationscanbemadeinmodeling
theparticularpart.
6. Primary members of structure are long and thin like a beam then
idealizationisrequired.
7.Localbehavioratthejointsofbeamsorotherdiscontinuitiesarenot
ofprimaryinterestsonospecialmodelingoftheseareaisrequired.
8. Decorative or external features will be assumed insignificant to the
stiffness and the performance of the part and will be omitted from the
model.
MaterialAssumptions
1. Material remain in the linear regime. It is understood that either
stresslevelsexceedingyieldorexcessivedisplacementswillconstitutea
componentfailure.Thatisnonlinearbehaviorcannotbeaccepted.
2.Nominalmaterialpropertiesadequatelyrepresentthephysicalsystem.
3.Materialpropertiesarenotaffectedbyloadrate.
4. Material properties can be assumed isotropic (Orthotropic) and
homogeneous.
5.Partisfreeofvoidsorsurfaceimperfectionsthatcanproducestress
risersandskewlocalresults.
6. Actual non linear behavior of the system can be extrapolated from the
linearmaterialresults.
7.Weldmaterialandtheheataffectedzonewillbeassumedtohavesame
materialpropertiesasthebasematerial.
8.Temperaturevariationsmayhaveasignificantimpactontheproperties
ofthematerialsused.Changeinmaterialpropertiesisneglected.
BoundaryConditionsAssumptions1.ChoosingproperBC’srequireexperience.
2. Using BC’s to represent parts and effects that are not or cannot be
modeled leads to the assumption that the effects of these un-modeled
entities can truly be simulated or has no effect on the model being
analyzed.
3. For a given situation, there would be many ways of applying boundary
conditions.Butthesevariousalternativescanbewrongiftheuserdoes
notunderstandtheassumptionstheyrepresent.
4.Symmetry/anti-symmetry/reflectivesymmetry/cyclicsymmetryconditions
ifexistscanbeusedtominimizethemodelsizeandcomplexity.
5.Displacementsmaybelowerthantheywouldbeiftheboundaryconditions
beingmoreappropriate.Stressmagnitudesmaybehigherorlowerdepending
ontheconstraintused.
FastenersAssumptions1.Residualstressduetofabrication,pre-loadingofbolts,weldingand/or
othermanufacturingorassemblyprocessesareneglected.
2.Boltloadingisprimarilyaxialinnature.
3.Boltheadorwashersurfacetorqueloadingisprimarilyaxialinnature.
4.Surfacetorqueloadingduetofrictionwillproduceonlylocaleffects.
5. Bolts, spot welds, welds, rivets, and/or fasteners which connect two
componentsareconsideredperfectandactsasrigidjoint.
6.Stressrelaxationoffastenersorotherassemblycomponentswillnotbe
considered.Loadonthreadedportionofthepartisevenlydistributedon
engagedthreads
7.Failureoffastenerswillnotbereflectedintheanalysis.
GeneralAssumptions1. If the results in the particular area are of interest, then mesh
convergencewillbelimitedtothisarea.
2.Noslippagebetweeninterfacingcomponentswillbeassumed.
3.Anyslidingcontactinterfaceswillbeassumedfrictionless.
4. System damping will be normally small and assumed constant across all
frequencies of interest unless otherwise available from published
literatureoractualtests.
5.Stiffnessofbearingsinradialoraxialdirectionswillbeconsidered
infinite.
6. Elements with poor or less than optimal geometry are only allowed in
areasthatarenotofconcernanddonotaffecttheoverallperformanceof
themodel.
When a system under load is analyzed with linear static analysis, the
linear finite element equilibrium equations are solved to calculate the
displacementcomponentsatallnodes.Theseresultsareusedtocalculate
the strained components. These strain results along with stress-strain
relationshiphelpstocalculatestresses.
The procedure given next is generic and can be applied on any model and
assembly. But, we will use a model to help you understand the complete
procedurewithrealworldproblems.
PERFORMINGSTATICANALYSISProblem:Wehaveacomponentwhichisfixedbyitsroundbossfeatureandloadof
980N(100kgfapprox)isappliedontheitsflattop;refertoFigure-1.
We need to find out the Factor of Safety of the model and make it
optimized.
Figure-1.Problemofstaticanalysis
Toperformthestaticanalysisonanymodel,makesurethatyouhaveopened
themodelfileinSolidWorks.Thefileusedinthisexamplecanbefoundin
the resource kit for this book. After opening the file follow the steps
givennext.
StartingtheStaticAnalysis•Openthepartonwhichyouwanttoperformtheanalysis.
•ClickontheSolidWorksSimulationbuttonfromtheSOLIDWORKSAdd-Instab of theRibbon to add Simulation tab in the Ribbon, if not addedalready.
•ClickontheDownarrowbelowtheStudyAdvisorbuttonandselecttheNewStudy tool from the drop-down. Refer to Figure-2. List of analysis
studiesthatcanbeperformed,willbedisplayed.
Figure-2.StartingAnalysis
• Click on the Static button if not selected. Specify the name of the
analysisintheeditboxdisplayedabovethelistofanalyses.
•ClickontheOKbuttonfromthePropertyManager.Static 1 tab will beaddedatthebottomofthemodelingareaintheStudyBar.Also,thetoolsrelatedtotheanalysiswillbedisplayedintheRibbon;refertoFigure-3.
Figure-3.Analysisenvironment
ApplyingMaterial•ClickontheApplyMaterialbuttonfromthePropertyManager.TheMaterialdialogboxwillbedisplayed;refertoFigure-4.
Figure-4.Materialdialogbox
•SelecttheCastAlloySteelfromtheleftareaofthedialogboxandselecttheApplybuttontoapplythematerial.
•ClickontheClosebuttontoclosethedialogbox.
ApplyingFixtures•ClickonthedownarrowbelowFixturesAdvisorintheRibbon.Thetoolsrelatedtofixtureswillbedisplayed;refertoFigure-5.
Figure-5.FixturesAdvisor
• Click on the Fixed Geometry button from the tool list. The FixturePropertyManagerwillbedisplayed;refertoFigure-6.
Figure-6.FixturePropertyManager
•Selecttheroundfaceofthemodeltomakeitfixed;refertoFigure-7.
Figure-7.Fixedgeometry
•ClickontheOKbuttonfromthePropertyManagertofixtheroundface.
Now, we need to specify the loads that are actually occurring on the
component.
ApplyingLoads• Click on the down arrow below External Loads Advisor button in the
Ribbon.Listofthetoolsrelatedtoloadswillbedisplayed;refertoFigure-8.
Figure-8.Externalloadsadvisor
•ClickontheForcebuttonfromthelist.TheForce/TorquePropertyManagerwillbedisplayedasshowninFigure-9.
Figure-9.ForceTorquePropertyManager
•SelectthefaceasshowninFigure-10toapplytheforceload.
Figure-10.Faceselectedforapplyingload
•ClickintheForceValueboxinthePropertyManagerorinthemodelingarea and enter the value as 980 which is equal to 100 Kilograms of
weight. Refer to Figure-11. Note that you can change the unit of force
fromtheUnitdrop-downtoenter100kgfor220lbf.
Figure-11.Valuespecifiedforload
•ClickontheOKbuttonfromtheForce/TorquePropertyManager.Theforcewillbeappliedontheselectedface.
Forthisparticularproblem,wedonotrequireanyconnectiontobeapplied
sincethisisnotanassembly.Now,wearereadytodividethemodelinto
smallelementswiththehelpofmeshing.
MeshingthemodelNotethatyoucanskipthisstepifyoudonotwanttoexplicitlydefine
the element size for mesh. While running the analysis, system will
automatically create the suitable mesh for you. To explicitly define the
sizeofmeshelements,followthestepsgivennext.
•ClickonthedownarrowbelowtheRunbuttonintheRibbon.Thelistoftoolswillbedisplayed;refertoFigure-12.
Figure-12.CreateMeshtool
•ClickontheCreateMeshtoolfromthelist.TheMeshPropertyManagerwillbedisplayed;refertoFigure-13.
•ClickontheMeshParameterscheckbox.Therolloutwillexpandandtheoptionsrelatedtoelementsizeandtolerancewillbedisplayed;referto
Figure-14.
Figure-13.MeshPropertyManager
Figure-14.MeshParameters
•Setthedesiredvaluesintheparameterboxesintherolloutandclickon
theOK button from the PropertyManager. Note that the smaller value
given in the boxes will make the analysis slower because of more
calculations.ThemeshedmodelwillbedisplayedasinFigure-15.
Figure-15.Meshedmodel
•Tochangethemeshingforaparticularareaofthemodel,right-clickon
theMesh node in the Analysis Manager displayed at the left of the
modelingarea.Ashortcutmenuwillbedisplayed;refertoFigure-16.
•ClickontheApplyMeshControlbutton.TheMeshControlPropertyManagerwillbedisplayedasshowninFigure-17.
Figure-16.Meshingsimplification
Figure-17.MeshControlPropertyManager
• Select the faces of the model for which you want to change the mesh
elementssizes;refertoFigure-18.
Figure-18.Facesforchangingmeshsize
•MovethesliderintheMeshDensityrollouttowardscoarseorfineasperyour requirement. In this case, the selected area will be facing more
stressandweareconcernedmoreaboutthisarea.So,wewillmakefine
meshattheselectedfaceswithelementsizeof1.2mm.
•ClickontheOKbuttonfromthePropertyManagertocreatetheupdatedmesh.Notethatincreasingordecreasingtheelementsizewillalsoaffect
theaccuracyofresults.Decreasingtheelementsizegivesmoreaccurate
resultsbuttakemoreprocessing.
RunningtheAnalysis•ClickontheRunbuttonfromtheRibbon.Thesystemwillstartsolvingtheanalysis.
• After the processing is complete, the result of analysis will be
displayed;refertoFigure-19.
Figure-19.Analysisresult
• By default, results related to stress (vonMises) are displayed in the
modelingarea.
• To check Displacement and Strain related results, double-click on the
respectiveoptionfromtheAnalysisManagerintheleft.
Results(FactorofSafety)• To check results other than the default displayed, right-click on the
ResultsnodefromtheAnalysisManager.Ashortcutmenuwillbedisplayed;
refertoFigure-20.
• Click on theDefine Factor Of Safety Plot option to display the resultsrelated toFactorOf Safety. TheFactor of Safety PropertyManager will bedisplayedasshowninFigure-21.
Figure-20.Shortcutmenuforresults
Figure-21.FactorofSafetyPropertyManager
•Ifyouhaveaspecialcriteriaforcheckingsafetyfactorthenselectthe
respectiveoptionfromtheCriteriondrop-downintheStep1of3rolloutotherwise system will check the material properties and automatically
decidethebestcriteria.
•ClickontheOKbuttonfromthePropertyManager.TheFactorofSafetyplotwillbedisplayedinthemodelingarea;refertoFigure-22.
Figure-22.FactorofSafetyplot
Optimizingproduct•Ifyoucheckintheresultsdisplayedabovethemodel,theFactorofsafetydistributionMinFOS=0.7isdisplayedwhichshowsthatthemodelisnotsafeatthelocationsdisplayedindarkredcolor.Notethatforobjectto
besafeforloading,theFOSshouldbeabove1.•Here,weneedtoeitherchangethematerialorincreasethethicknessof
theobjecttosustaintheappliedload.
•Inthiscase,wechangethematerialtoAlloySteel.Todoso,right-clickon theMaterial node in theAnalysis Manager. A shortcut menu will bedisplayedasshowninFigure-23.
•SelecttheApply/EditMaterialfromthemenu.TheMaterialdialogboxwillbedisplayed.
•SelecttheAlloySteelmaterialfromthelefttableandclickontheApplybuttontoapplythematerial.
•ClickontheClosebuttonfromthedialogboxtocloseit.
Figure-23.Shortcutmenuformaterial
•Sincethematerialischanged,weneedtoruntheanalysisagain.Todo
so,clickontheRun button from theRibbon. The analysis will re-runandresultswillbedisplayed.
• Double-click on the Factor of Safety1 (-FOS-) node from the AnalysisManager.TheresultswillbedisplayedasshowninFigure-24.
Figure-24.UpdatedFactorofSafetyresults
•Now,thefactorofsafetyis2.5i.e.above1.So,ourproductcansustaintheappliedload.
SHELLMANAGERYoucanmanagealltheshells/surfacesatasingleplacebyusingtheShellManager. Shells are generally used to represent parts that have low
thickness like sheetmetal parts. The advantage of using shells lies in
element type used for them during meshing. For solid objects 3D elements
are used but for shells 2D elements like linear triangular and parabolic
triangularelementsareused.Theanalysisperformedusing2Delementsis
faster.TheproceduretousetheShellManagerisgivennext.
• Before using ShellManager, you should have a surface model; refer toFigure-25. This model is a representation of sheet metal part with
thicknessof3mmatthetopcurvedfaceand5mmontheotherfaces.
Figure-25.Surfacemodel
•Toassignthicknesstothemodel,clickontheShellManager tool fromthe Simulation CommandManager of the Ribbon. The Shell ManagerPropertyManager will be displayed with Shell Manager pane; refer to
Figure-26.
Figure-26.ShellManager
• If the object has uniform thickness then click in the cell under
ThicknesscolumnintheShellManagerpaneandenterthedesiredthicknessvalue; refer to Figure-27. Make sure that you have selected right unit
fromtheUnitcolumninthepane.
Figure-27.Uniformthicknessapplied
•Ifyouwanttospecifydifferentthicknesstodifferentfacesthenclick
intheselectionboxinPropertiesrolloutoftheShellManagerandselect
thefaces;refertoFigure-28.
Figure-28.SelectionboxinPropertiesrollout
•ClickontheOKbuttonfromtheShellManager.Awarningmessagewillbedisplayed. Click onYes to apply new selection of faces for shell. ThefaceswillbedisplayedintheShellManagerpane;refertoFigure-29.
Figure-29.ShellManagerpane
•Onebyone,enterthedesiredsheetthicknessforeachface.Makesure
thatyoupressENTERafterspecifyingthicknessinthecells.• Similarly, you can select other parameters like material, offset type
etc. for individual faces. Figure-30 shows the faces assigned with
differentmaterials.
Figure-30.Faceswithdifferentmaterialandthickness
•Afterspecifyingtheparameters,clickontheOKbuttonfromtheShellManager.Now,youcancontinuewiththeanalysisjustlikeasolidpart(withhybridmaterial).
PERFORMINGSTATICANALYSISUSINGSTUDYADVISOR
Earlierinthischapter,wehaveperformedthestaticanalysisbyselecting
eachoftherequiredoptionfromthelistoftoolsintheRibbon.Wecanuse the Study Advisor to perform all the steps related to analysis. ThestepstousetheStudyAdvisoraregivennext.
StartingtheStaticAnalysis•Openthepartonwhichyouwanttoperformtheanalysis.
•ClickontheSolidWorksSimulationbuttonfromtheSOLIDWORKSAdd-Instab of theRibbon to add Simulation tab in the Ribbon, if not addedalready.
• Click on the Down arrow below the Study Advisor button and select theStudyAdvisor tool from the drop-down. The study page of theSimulationAdvisorwillbedisplayedasshowninFigure-31.
Figure-31.StudypageofSimulationAdvisor
• Currently, we are planning to perform the stress analysis. For that,
click on the I am concerned about excessive deformation or stresses linkbutton. The second page of Study will be displayed in the SimulationAdvisor;refertoFigure-32.
Figure-32.SecondpageStudy
•Usingtheoptionsinthispage,wecancheckthedeformationplotforthe
present analysis. Deformation plot displays the visualization of
deformationfortheanalysis.
1. If you want to check the deformation for a specific
part/face/edge/vertexthenclickontheIneedtolimitdeformationinspecifiedregions of my model(parts, faces, edges, vertices) link button. The SensorPropertyManagerwillbedisplayedasshowninFigure-33.
Figure-33.SensorPropertyManager
2. Select the part/face/edge/vertex for which you want to check the
deformation; refer to Figure-34 and click on the OK button from the
PropertyManager.ThepagerelatedtomaterialfailurewillbedisplayedintheSimulationAdvisor.
Figure-34.Faceselectedfordeformationtesting
•IfyouwanttospecifylimitfordeformationthenclickontheNothinginmy design may deform more than a specified amount. The SensorPropertyManagerwillbedisplayed.
1.ClickontheAlertrollouttoexpandit.TheoptionsintherolloutwillbedisplayedasshowninFigure-35.
2. Click in the edit box and specify the limit of deformation. If the
deformationcrossesthespecifiedvaluethenanalertwillbedisplayed.
3. ClickOK button from the PropertyManager. Page related to materialfailurewillbedisplayedintheSimulationAdvisor;refertoFigure-36.
Figure-35.SensorPropertyManagerwithAlertoptions
Figure-36.SimulationAdvisorwithpagerelatedtomaterialfailure
• Click on the I want to check material failure link button to check for
materialfailure.Thenextpageformaterialfailurewillbedisplayedin
theSimulationAdvisor;refertoFigure-37.
•ClickontheIdon’tknowwheretoexpectfailure.Checkthewholemodellinkbuttontocheckthewholemodelformaterialfailure.YoucanselecttheIammostconcernedaboutfailureatspecificlocationsinmymodellinkbuttonifyou want to check the material failure for a specific portion. In this
case, we have selected the first link button. On doing so, again the
SensorPropertyManagerisdisplayedwhereyoucanspecifythealertformaximum stress. Note that the maximum bearable stress is generally
obtainedbymaterialproperties.
•ClickontheOKbuttonfromthePropertyManagerandthenclickontheNextlinkbuttonfromtheSimulationAdvisor,thenameofthestudythatsuitsyourrequirementswillbedisplayed;refertoFigure-38.
Figure-37.SimulationAdvisorwithanotherpagerelatedtomaterialfailure
Figure-38.SimulationAdvisorwithStudyname
•ClickontheCreateaStaticStudylinkbuttonandthenclickontheNextlinkbuttonfromtheSimulationAdvisor.TheBodiesandMaterialpagewill
bedisplayedintheSimulationAdvisor.
• Click on the Next button from the pages related to symmetry will be
displayed; refer to Figure-39. Note that if you apply symmetry then
calculationtimeforanalysiswillbereduced.
Figure-39.SimulationAdvisorwithsymmetrypage
• Click on the desired link from the SimulationAdvisor. For the currentexample, click on theMirrored link button and then click on theAddsymmetry fixtureonsolid faceslinkbuttonfromtheSimulationAdvisor. TheFixturePropertyManagerwillbedisplayed;refertoFigure-40.
•Youcanapplythesymmetryoptionasdiscussedinpreviouschapter.
•AfteryouarefinishedwiththesymmetrythenclickontheFinishedwithSymmetrylinkbutton.Thepagerelatedtobodysetupwillbedisplayed;refertoFigure-41.
Figure-40.FixturePropertyManagerwithsymmetryoption
Figure-41.Pagerelatedtobodysetup
• Click on theChange body setup link button to specify setting for thebody.Youaredisplayedamessageboxsayingthatyouneedtoright-click
onthebodyandselecttheTreatasoption.Right-clickonthenameofthemodel in theAnalysis Manager and select the desired treat as option;refer to Figure-42. The options related to the selected option will be
displayedintheformofPropertyManager.Actaccordingly.
• Now, click on theNext button from the body setup page of SimulationAdvisor.Thematerialpagewillbedisplayed;refertoFigure-43.
Figure-42.Treatasoptions
Figure-43.MaterialpageofSimulationAdvisor
•ClickontheChoosemateriallinkbuttontospecifythematerialforthecurrent model. TheMaterial dialog box will be displayed as discussed
earlier.Selectthematerial,clickontheApplybuttonandthenclickon
theClosebutton.TheappliedmaterialwillbedisplayedintheSimulationAdvisor.
•ClickontheNextbuttonfromtheSimulationAdvisor.TheInteractionspagewillbedisplayed;refertoFigure-44.
Figure-44.SimulationAdvisorwithInteractionpage
Now onwards, the path of usingSimulationAdvisor becomes very confusing.So,wewillgobacktoRibbonandselectthedesiredoptionfromthere.
•ClickontheFixturesAdvisorbuttonfromtheRibbon.TheoptionsrelatedtofixtureswillbedisplayedintheSimulationAdvisor;refertoFigure-45.
•ClickontheAddafixturelinkbutton.TheFixturePropertyManagerwillbedisplayedasdiscussedearlier.
• Select the bottom face of the current model; refer to Figure-46. And
clickontheOKbuttonfromthePropertyManagertoapplythefixture.
Figure-45.OptionsforfixtureinSimulationAdvisor
Figure-46.Faceselectedforfixture
• Click on theExternal Loads Advisor button from theRibbon. The loadspageofSimulationAdvisorwillbedisplayed;refertoFigure-47.
Figure-47.LoadspageofSimulationAdvisor
• Click on theAdd a load link button. The Force/Torque PropertyManagerwillbedisplayedasdiscussedearlier.
•Selectthetopfaceofthemodelandspecifythevalueofforceas392N;refertoFigure-48.
•ClickontheOKbuttonfromthePropertyManagertoapplytheforce.
• Click on theDone -Continue to nextAdvisor section link button from theSimulationAdvisor. TheMesh andRun page ofSimulationAdvisor will bedisplayedasshowninFigure-49.
Figure-48.Forceappliedontopface
Figure-49.MeshandRunpage
•ClickontheChangesettingslinkbuttonandthenspecifythedesiredmeshsizesforglobalorlocalareasofthemodel.
•Inourcase,weusethedefaultsettingsandclickontheRunTheStudylinkbutton.Firstmeshingwillbeprocessesandthentheanalysiswillbe
performed.Aftertheanalysisiscompleted,thentheresultspagewillbe
displayedintheSimulationAdvisorasshowninFigure-50.
•ClickonthePlaybuttonfromtheSimulationAdvisortochecktheresults.ClickontheStopbuttontostopanimation.
• Click on theEverything looks reasonable link button to check the otherresults.
•Next,ClickontheMaterialbreakingoryieldinglinkbuttonandthenShowFactor of Safety plot link button to plot theFactor of Safety result. Theresultwillbedisplayed;refertoFigure-51.
Figure-50.ResultpageofSimulationAdvisor
Figure-51.Factorofsafetyresult
•ClickontheSuggestionstoimprovedesignlinkbuttonandyouwillgettoknowthemethodstoincreasestrengthoftheproductifrequired;referto
Figure-52.
Figure-52.Suggestionstoimprovestrength
•Bydefault,theVon-misesstressplotisdisplayedbutsometimesweneed
otherplotsofstressalso.Todoso,right-clickontheResultsnodeintheAnalysisManager and select theDefine Stress Plot option. The StressPlotPropertyManagerwillbedisplayed;refertoFigure-53.
Figure-53.StressPlotPropertyManager
•ClickontheComponent drop-down and select theP1: 1st Principal Stressoptionfromthelistdisplayed.
• Click on the OK button from the PropertyManager. The plot will be
created.
STATICANALYSISONASSEMBLYProblem:WehaveanassemblyofwallbracketasshowninFigure-54.Thebracketis
boltedtovirtualwallwiththehelpoffoundationbolts.Loadof100kgis
appliedattheflatendofthesupport.Checkthecomponent/componentsthat
are failing in the static analysis. The part files are available in the
resourcesofthisbook.
Figure-54.Assemblyofwallbracketforstaticanalysis
UnderstandingProblem:In this case, we have an assembly of three components connected to each-
other. The base plate is attached to a virtual wall with the help of
foundationbolts.Thearmisconnectedtobasewiththehelpofapin.Now,
wewillapplytheseconditionsinSolidWorksSimulation.
StartingAnalysis• Open the assembly file of model on which you want to perform the
analysis.
•ClickontheSolidWorksSimulationbuttonfromtheSOLIDWORKSAdd-Instab of theRibbon to add Simulation tab in the Ribbon, if not addedalready.
•ClickontheDownarrowbelowtheStudyAdvisorbuttonandselecttheNewStudy tool from the drop-down. List of analysis studies that can be
performed,willbedisplayed.
• Click on the Static button if not selected. Specify the name of the
analysisintheeditboxdisplayedabovethelistofanalyses.
•ClickontheOKbuttonfromthePropertyManager.Static 1 tab will beaddedatthebottomofthemodelingareaintheStudyBar.Also,thetoolsrelatedtotheanalysiswillbedisplayedintheRibbon.
ApplyingMaterialtoPartsofAssemblyThere are two ways to apply material to the parts of assembly; Applying
same material to all the components and applying different materials to
componentsoftheassembly.Wewillbeapplyingdifferentmaterialtothe
assemblycomponents.
•Right-clickontheBasecomponentfromthePartscategoryintheAnalysisManager.Ashortcutmenuwillbedisplayed;refertoFigure-55.
Figure-55.Shortcutmenupartsofassembly
• Click on the Apply/Edit Material option from the shortcut menu. The
Materialdialogboxwillbedisplayed.
•SelecttheCastAlloySteelfromtheleftareaofthedialogboxandclickon theApply button. Click on theClose button from the dialog box toexit.
•Similarly,applyalloysteeltoarmandstud.
Note that you want to apply same material to all the components in the
assembly then right-click on the Parts category and click on the ApplyMaterialtoAlloptionfromtheshortcutmenudisplayed;refertoFigure-56.
Figure-56.ApplyMaterialtoAlloption
SettingGlobalContactsBydefault, SolidWorks Simulation applies bonded contacts between all the
components in the assembly which means all the components are perfectly
bonded and behave as if they are single model entity. But we need a no
penetration contact in which all the components of assembly are separate
and make affect on each other due to load applied. The procedure is
discussednext.
• Expand theComponentContacts sub-category in theConnections categoryintheAnalysisManager;refertoFigure-57.
• Right-click on theGlobal Contact option and select the Edit Definitionoption from the shortcut menu displayed. The Component ContactPropertyManagerwillbedisplayedasshowninFigure-58.
Figure-57.Expandedcomponentcontactssub-category
Figure-58.ComponentContactPropertyManagerforassembly
•SelecttheNoPenetrationradiobuttonfromtheContact Type rollout inthePropertyManager.
•ClickontheOKbuttonfromthePropertyManagertoexit.
SettingContactManuallyThis section is just for information and does not affect the results of
currentanalysis.Youcanskipthissectionifyouwishto.
•ClickontheContactSettoolfromtheConnectionsAdvisordrop-downintheRibbon. The Contact Sets PropertyManager will be displayed; refer to
Figure-59.
• Select the Automatically find contact sets radio button from the
PropertyManager and select theTouching faces radio button to highlightallthecontactsthatarecreatedbycontactsofassemblyparts.
•Onebyoneselectallthecomponentsofassemblyforwhichyouwantto
createthecontactsets;refertoFigure-60.
Figure-59.ContactSetsPropertyManagerforassemblycomponents
Figure-60.Componentsofassemblyselected
• Click on the Find contact sets button in the Components rollout. The
contactsetswillbedisplayedinResultsrollout.
•SelectthecontactsetandsetthedesiredconditionintheTypedrop-down.
• After setting all the contacts, click on the OK button from the
PropertyManagertoexit.
CreatingVirtualWallAsthenamesuggests,virtualwallactsasavirtualwallfortheassembly.
Wewilluseitlatertofastenfoundationbolts.
•ClickontheContactSetstoolfromtheConnectionsAdvisor drop-down intheRibbon.TheContactSetsPropertyManagerwillbedisplayed.
•SelectVirtualWalloptionfromtheTypedrop-downintheTyperolloutofthePropertyManager;refertoFigure-61.
Figure-61.VirtualWalloption
•SelecttheflatbackfaceofthebasepartandthenclickintheTargetPlaneselectionbox;refertoFigure-62.
Figure-62.Faceselectedforvirtualwall
•ExpandthedesigntreefromviewportandselecttheFrontplaneofBase
part;refertoFigure-63.
Figure-63.Planeselectedforvirtualwall
•ClickontheOKbuttonfromthePropertyManager.
CreatingFoundationBoltconnectionFoundationboltsgiveusthebenefitoffixinganyobjecttothewall/floor
usingbolts.Theproceduretocreateconnectionisgivennext.
• Click on the Bolt tool from the Connections Advisor drop-down in the
Ribbon. The Connectors PropertyManager will be displayed with the
optionsrelatedtobolts.
•SelecttheFoundationBoltbuttonfromtheTyperollout;refertoFigure-64.
Figure-64.FoundationBoltbutton
•Selecttheroundedgeofaholeinthebaseplate;refertoFigure-65.
Figure-65.Edgeselectedforfoundationbolt
•ClickintheTargetPlaneselectionboxinthePropertyManagerandselecttheFrontplaneofbasepartusingtheDesignTreeinviewport.
• Move downward inPropertyManager and set the Torque value of pre-load600N.m.
• Click on theOK button from thePropertyManager. The foundation boltwillbecreated.
•Similarly,createthefoundationboltsforotherholesofbase.
ApplyingLoad•ClickontheForcetoolfromtheExternalLoadsAdvisordrop-downintheRibbon.TheForce/TorquePropertyManagerwillbedisplayed.
•SelecttheflatfaceoftheArmpartandselecttheMetric option fromtheUnitdrop-downinthePropertyManager;refertoFigure-66.
Figure-66.Faceselectedforload
• Specify the value of load as 100 in the Force value edit box in
PropertyManager.
•ClickontheOKbuttonfromthePropertyManager.
Meshing•ClickontheCreateMeshtoolfromtheRundrop-downintheRibbon.TheMeshPropertyManagerwillbedisplayed.
•MovetheMeshDensityslidertowardsCoarse;refertoFigure-67andclickontheOKbuttontocreatemeshing.Thiswillreducetheprocessingtime
of analysis but reduce the accuracy also. If you have good system
configurationandyouareveryseriousaboutresultsofthisanalysisthen
movetheslidertowardsFine.
Figure-67.MeshPropertyManagerwithCoarsedensity
RunningAnalysisBefore running analysis, we need to select the Direct Sparse solver for
solving analysis because we have used the No penetration contact in our
analysis.Theuseofdifferentsolversisdiscussednext.
AutomaticThesoftwareselectsthesolverbasedonthestudytype,analysisoptions,
contactconditions,etc.Someoptionsandconditionsapplyonlytoeither
DirectSparseorFFEPlus.
DirectSparseSelecttheDirectSparse:•whenyouhaveenoughRAMandmultipleCPUsonyourmachine.
•whensolvingmodelswithNoPenetrationcontact.
•whensolvingmodelsofpartswithwidelydifferentmaterialproperties.
Forevery200,000dof,youneed1GbofRAMforlinearstaticanalysis.The
DirectSparsesolverrequires10timesmoreRAMthantheFFEPlussolver.
FFEPlus(iterative)TheFFEPlussolverusesadvancedmatrixreorderingtechniquesthatmakesit
moreefficientforlargeproblems.Ingeneral,FFEPlusisfasterinsolving
largeproblemsanditbecomesmoreefficientastheproblemgetslarger.
Forevery2,000,000dof,youneed1GbofRAM.
LargeProblemDirectSparseBy leveraging enhanced memory-allocation algorithms, the Large Problem
Direct Sparse solver can handle simulation problems that exceed the
physicalmemoryofyourcomputer.
IfyouinitiallyselecttheDirectSparsesolverandduetolimitedmemory
resourcesithasreachedanout-of-coresolution,awarningmessagealerts
youtoswitchtotheLargeProblemDirectSparse.
The Large Problem Direct Sparse (LPDS) solver is more efficient than the
FFEPlusandDirectSparsesolversattakingadvantageofmultiplecores.
IntelDirectSparseTheIntelDirectSparsesolverisavailableforstatic,thermal,frequency,
lineardynamic,andnonlinearstudies.
By leveraging enhanced memory-allocation algorithms and multi-core
processing capability, the Intel Direct Sparse solver improves solution
speedsforsimulationproblemsthataresolvedin-core.
ProceduretoselectDirectsparsesolverisgivennext.
• Right-click on the analysis name inAnalysis Manager. A shortcut menuwillbedisplayed;refertoFigure-68.
Figure-68.Shortcutmenuforpropertiesofanalysis
•ClickonthePropertiesoptionfromtheshortcutmenu.TheStatic dialogboxwillbedisplayedwithpropertiesofanalysis.
•SelecttheDirectsparsesolveroptionfromthedrop-downintheSolverareaofthedialogbox;refertoFigure-69.
Figure-69.Directsparsesolveroption
•ClickontheOKbuttonfromthedialogbox.
Now,wearereadytoruntheanalysis.
•ClickontheRunbuttonfromtheRibbonandchecktheresults.Youwillgetlargedisplacementintheanalysis.Thisisthestagewhereweneedto
changethedesiredmodeltosustaintheload.
Onesolutiontothisproblemcanbeaddingribtothebasepartasshownin
Figure-70.Thechangedbasepartisalsoavailableintheresourceforthe
book.Replaceitwiththebasepartinassemblyandre-runtheanalysisto
seethemagic.
Figure-70.Changedbasepart
ADAPTIVEMESHINGThere are three type of meshing available in SolidWorks Simulation;
StandardMeshing, h-adaptive meshing, and p-adaptive meshing. Most of the
time,thestandardmeshingdoestheworkinstaticanalyses.But,whenwe
needmoreaccurateresultsaredeformingareathenweuseh-adaptiveorp-
adaptivemeshingschemes.Moredetailonh-adaptiveandp-adaptiveisgiven
next.
h-AdaptiveMeshingInh-adaptivemeshing,systemsolvestheanalysisbyusingstandardmeshing
and then system solves the analysis again with a refined mesh at the
locations of strain. This process continues up to the number of steps
definedbyusortillthedesiredaccuracyisachievedfromtheanalysis.
Thisrepetitionofanalysisincreasestheprocessingtimesothistypeof
meshing is suggested when you are concerned about high accuracy. The
proceduretoapplyh-adaptivemeshinginthestaticstudyisgivennext.
• After starting the Static study in SolidWorks Simulation, click on theStudyPropertiestoolfromtheStudyAdvisordrop-downintheRibbon.The
StaticdialogboxwillbedisplayedasshowninFigure-71.
Figure-71.Staticdialogbox
• Click on theAdaptive tab from the dialog box. The options related toadaptivemeshingwillbedisplayed;refertoFigure-72.
Figure-72.Partialviewofadaptiveoptions
•Clickontheh-adaptiveradiobuttonfromtheAdaptivemethodareaofthedialogbox.Theoptionsrelatedtoh-adaptivemeshingwillbecomeactive;
refertoFigure-73.
Figure-73.h-adaptiveoptions
•SetthetargetaccuracybyusingthesliderforTargetaccuracy.
• Set the accuracy bias using the Accuracy bias slider. If you want toconcentrateonareaunderhigherstressthenmovetheslidertowardsleft
i.e.Local(Faster).Ifyouwanttoincreaseaccuracyforthewholemodelthenmovetheslidertowardsrighti.e.Global(Slower).
•SetthenumberofloopsintheMaximumno.of loopsspinnertosetthenumberoftimesanalysisshouldrunforaccuracy.
•SelecttheMeshcoarseningcheckboxtomakemeshingcoarseintheareaswhichareofnointerest.
•ClickontheOKbuttonfromthedialogboxandruntheanalysistocheck
thedifferenceinmeshingandresults.Figure-74showsonsuchexample.
Note that if the specified accuracy is not reached in number of loops
specifiedinthedialogboxtheneachtimeyouclickontheRunbuttontore-runthestudy,theresultswillbecomeaccuratefurthertillthedesired
accuracyisachievedincaseofh-adaptivemeshing.
Figure-74.Standardandh-adaptivemeshing
p-AdaptiveMeshingInh-adaptivemeshing,wehaveseenthatsizeofthemeshelementreduces
and number of elements increase in the area of interest. In p-Adaptive
meshing, the order of mesh element changes. We have earlier discussed in
this book that SolidWorks Simulation provides beam element for linear
problems,triangularelementsfor2Dproblems,andtetrahedralelementsfor
3Dproblems.So,instandardmeshinghighestorderelementistetrahedral
butthisisnottrueifyouhaveselectedp-adaptivemeshing.Inthiscase,
theelementscanbefrominitial2ndordertomaximum5thorderdependingon
analysisrequirements.Theproceduretousethep-adaptivemeshingisgiven
next.
•Clickonthe p-adaptive radio button from the Adaptive tab in theStaticdialogboxdiscussedearlier.Theoptionswillbedisplayedasshownin
Figure-75.
Figure-75.p-Adaptiveoptions
•Setthestoppingconditionforpolynomialincrementofmeshelementsby
usingthedrop-downandeditboxinfirstlineofp-Adaptiveoptionsarea
of the dialog box. There are three options in the drop-down; RMS Res.
Displacement, RMS von Mises Stress, and Total Strain Energy. Select the
desiredoptionandsetthepercentagevalueofchangetobeachievedwhile
makingresultsaccurate.Ifthechangeinselectedparametersislessthan
thispercentagethenloopwillnotrunfurther.
•TheUpdateelementswithrelativeStrainEnergyerrorofeditboxisusedtospecifythemaximumallowederrorvalueintheStrainenergyresults.The
elementsthataregeneratingerrormorethanthisvaluewillbeupgraded.
• Specify the starting polynomial order and maximum polynomial order by
using the respective spinners in the dialog box. Note that minimum
polynomialordercanbe2andmaximumpolynomialordercanbe5.
• Specify the number of loops up to which the analysis should run for
accuracy.Themaximumnumberofloopscanbe4.
•Afterspecifyingtheparameters,clickontheOKbuttonfromthedialog
boxandruntheanalysis.
Figure-76 shows the example used for h-adaptive meshing solved by p-
adaptivemeshing.
Figure-76.p-adaptivemeshingresults
SUBMODELINGSTUDYWehaveworkedearlieronanassemblyofwallbracketandfoundthatthe
reason of failure was base of wall bracket for which we added ribs as
solution. But sometimes our components are hidden in the assembly and we
are not able to check the stress without explicitly running analysis on
them.Tosolvethisproblem,weuseSubmodelingstudy.InSubmodelingstudy
the selected portion of assembly is analyzed for the loads that are
applicableonitduringanalysisofwholeassembly.Inthisway,youdonot
requirecalculationsofremoteload.Notethatthisoptionisavailablefor
StaticandNon-linearstaticanalysesonly.
Submodeling is based on the St. Venant’s principle. The St. Venant’s
principlestatesthatthestressesonaboundaryreasonablydistantfroman
applied load are not significantly altered if this load is changed to a
statically equivalent load. The distribution of stress and strain is
alteredonlyneartheregionsofloadapplication.Youmaycutaportionof
themodel,refinethemesh,andrunanalysisonlyfortheselectedportion
providedthatdisplacementsareproperlyprescribedatthecutboundaries.
If displacement results from the parent study are accurate, then these
displacementsare considered as boundary conditions at the cut boundaries
for the submodeling study. So, may need to use adaptive meshing for
accurateresultsofdisplacement.Notethattheboundariesofthesubmodel
mustbeadequatelyfarfromstressconcentrationareas.
Thereareafewconditionstousesubmodelingstudylike,
•Thestudytypemustbestaticornonlinearstaticwithmorethanonebody
and not be a submodeling study itself. The parent study cannot be a 2D
Simplificationstudy.
• The selected bodies of the submodel cannot have No penetration contact
with unselected bodies that creates contact pressure across the cut
boundary.
• The selected bodies of the submodel cannot share connectors with
unselected bodies. For example, the piping assembly below is not a
suitable parent model. A submodel of two parts is connected to the
excludedthirdpartwithbolts.
•Thecutboundaryofthesubmodelcannotcutthroughbodies.
• The cut boundary of the submodel cannot cut through a bonded contact
definedbyeitherbeam-to-beamjointsorshelledge-to-shelledgejoints.
•Thebondedcontactatthecutboundaryofthesubmodelisformulatedwith
anincompatiblemesh.
The procedure to use submodeling study is discussed next through an
example.
WehaveperformedastaticanalysisonassemblygiveninFigure-77.Now,we
want to check the results for Part 2 more precisely. To do so, we will
createasubmodelingstudyforwhichthestepsaregivennext.
Figure-77.Assemblywithboundaryconditions
•Right-clickontheanalysisnameintheAnalysisManagerandclickontheCreateSubmodelingStudyoptionfromtheshortcutmenudisplayed;refertoFigure-78. The Submodeling Information dialog box will be displayed asshowninFigure-79.
Figure-78.CreateSubmodelingStudyoption
Figure-79.SubmodelingInformationdialogbox
•ClickontheOKbuttonfromthedialogbox.Youareaskedtoselectthe
bodiesthatyouwanttoincludeinsubmodelingstudy.
•Selectthecheckboxforthepartthatyouwanttoincludeinstudyfrom
theDefineSubmodelPropertyManager;refertoFigure-80.
Figure-80.DefineSubmodelPropertyManager
• Click on theOK button from thePropertyManager. All the un-selectedbodieswillbeexcludedfromthestudyandthestudyenvironmentwillbe
displayed;refertoFigure-81.
Figure-81.Submodelingstudyinterface
• Click on the Run This Study button from the Ribbon. The result of
assembly load will be displayed on the selected components; refer to
Figure-82.
Figure-82.Resultofsubmodelanalysis
LOADCASEMANAGERUsingLoadCaseManager,wecancreatedifferentcasesofloadingonthecomponent and we can simultaneously judge the results of component in
differentloadingconditions.Thisfeaturehelpsusfindoutthestability
ofcomponentinentirelydifferentconditions.Forexample,weneedtotest
a component in a high temperature environment of 80 degree Celsius and a
lowtemperatureenvironmentof-20degreeCelsiuswithdifferentloadsof
20tonneand15tonne(Ihopeyouknowdifferencebetweentonandtonne).
Todosuchanalyses,wefindloadcasemanagerveryhelpful.Notethatload
case manager is available for static analysis only and that too when p-
adaptiveandh-adaptivemeshingisnotselected.Now,wewilldiscussthe
useofloadcasemanagerwithanexample.
We have a static analysis performed on an alloy steel block; refer to
Figure-83.
Figure-83.Staticanalysiswithboundaryconditions
•Right-clickontheanalysisnameintheAnalysisManagerandselecttheLoad Case Manager option from the shortcut menu displayed; refer to
Figure-84.TheLoadCaseManagerwillbedisplayed;refertoFigure-85.
Figure-84.LoadCaseManageroption
Figure-85.LoadCaseManager
•ClickonthetogglebuttonsintheManagertodisplayorhidefixtures,
loads,andconnectors.
•Clickonthe+signunderPrimaryLoadCasesnode.Anewloadcasewill
beadded;refertoFigure-86.
Figure-86.Addingloadcase
•ClickonSuppressoptioninthefieldforwhichyouwanttospecifynewvalue.Adrop-downwillbedisplayed;refertoFigure-87.
Figure-87.Suppressoptionforloads
•Selecttheearlierspecifiedvaluefromthedrop-downandspecifythenew
valuelike80.
•Similarly,specifyvalueofotherloadsintherespectivefields.
•Afterspecifyingthevaluesofcase1,againclickonthe+signinthePrimary Load Case node and repeat the procedure to specify loads for
secondcase.
•YoucancombinevariousloadcasesbyusingtheLoadCaseCombinationsnodeoptions.Clickonthe+signunderLoadCaseCombinationsnode.TheEditEquation(LoadCaseCombination)dialogboxwillbedisplayed;refertoFigure-88.
Figure-88.EditEquation(LoadCaseCombination)dialogbox
•SetthedesiredloadingequationandclickontheOKbuttontocombine
variousloadingcases.
•Aftersettingthedesiredparameters,clickontheRunbuttonfromtheLoad Case Manager. The system will solve various cases and display
resultsinviewport.
•Tochecktheresultofaloadingcase,clickonitsnamefromResultsViewtabintheLoadCaseManager;refertoFigure-89.
Figure-89.Resultforloadcase
•ClickontheReportbuttontocreatereportforloadingcases.
•ClickontheClosebuttonatthetop-rightofLoadCaseManagertocloseit.
PRACTICE1
Considerarectangularplatewithcutout.Thedimensionsandtheboundary
conditionsoftheplateareshowninFigure-90.Itisfixedononeendand
loadedontheotherend.Underthegivenloadingandconstraints,plotthe
deformed shape. Also, determine the principal stresses and the von Mises
stressesinthebracket.Thicknessoftheplateis0.125inchandmaterial
isAISI1020.
Figure-90.DrawingforPractice1
PRACTICE2
Downloadthemodelforpractice2ofchapter3fromtheresourcekitand
performthestaticanalysisusingtheconditionsgiveninFigure-91. Find
outtheFactorofSafetyforthemodel.
Figure-91.Practice2
PRACTICE3
Downloadthemodelofchairinchapter3fromtheresourcekitandperform
thestaticanalysisusingtheconditionsgiveninFigure-92.Thematerial
used for manufacturing chair is PET (Polyethylene terephthalate). Check
whetheritissafe.Also,checkwhetherRikishi(wrestler)cansitonthis
chairwithoutanyconsequences.Hisweightis193Kg.
Figure-92.Practice3forStaticAnalysis
SELF-ASSESSMENT
Q1.Whichofthefollowingisnotanassumptionforstaticanalysis?
a.Theloadsapplieddoesnotvarywithtime.
b.Thechangeinstiffnessduetoloadingisneglected.
c.Materialpropertiesarenotaffectedbyloadrate.
d.Weldmaterialandtheheataffectedzonewillbeneglected.
Q2.Whichofthefollowingisnotanassumptionforstaticanalysis?
a.Residualstressduetofabrication,pre-loadingofbolts,weldingand/or
othermanufacturingorassemblyprocessesareneglected.
b.Boltloadingisprimarilyaxialinnature.
c.Failureoffastenerswillbereflectedintheanalysis.
d.Surfacetorqueloadingduetofrictionwillproduceonlylocaleffects.
Answerthefollowingquestionsincontextofgeneralanalysisassumptions:
Q3. If the results in the particular area are of interest, then mesh
convergenceshouldbelimitedtothisarea.(T/F)
Q4.Noslippagebetweeninterfacingcomponentswillbeassumed.(T/F)
Q5.Stiffnessofbearingsinradialoraxialdirectionswill
beconsideredinfinite.(T/F)
Q6.Whenasystemunderloadisanalyzedwithlinearstaticanalysis,the
linear finite element equilibrium equations are solved to calculate the
displacementcomponentsatallnodes.(T/F)
Q7.Forsolidobjects3Delementsareusedbutforshells2Delementslike
lineartriangularandparabolictriangularelementsareused.(T/F)
Q8.Youcanmanagealltheshellsatasingleplacebyusingthetoolfrom
Ribbon.
Q9. By default, SolidWorks Simulation applies …………. contacts between all
thecomponentsintheassembly.
Q10.……………boltsgiveusthebenefitoffixinganyobjecttothewall/floor
usingbolts.
Non-LinearStaticAnalysis
Chapter5
TopicsCovered
Themajortopicscoveredinthischapterare:
•Introduction
•StartingNon-LinearStaticAnalysis.
•ApplyingMaterial.
•DefiningFixtures
•Applyingloads
•DefiningConnections
•SimulatingAnalysis.
•Interpretingresults
NONLINEARSTATICANALYSISAllrealstructuresbehavenonlinearlyinonewayoranotheratsomelevel
ofloading.Insomecases,linearanalysismaybeadequate.Inmanyother
cases, the linear solution can produce erroneous results because the
assumptionsuponwhichitisbasedareviolated.Nonlinearitycanbecaused
bythematerialbehavior,largedisplacements,andcontactconditions.
Youcanuseanonlinearstudytosolvealinearproblem.Theresultscanbe
slightlydifferentduetodifferentprocedures.
Innonlinearfiniteelementanalysis,amajorsourceofnonlinearityisdue
totheeffectoflargedisplacementsontheoverallgeometricconfiguration
of structures. Structures undergoing large displacements can have
significant changes in their geometry due to load-induced deformations
whichcancausethestructuretorespondnonlinearlyinastiffeningand/or
asofteningmanner.
Forexample,cable-likestructuresgenerallydisplayastiffeningbehavior
onincreasingtheappliedloadswhilearchesmayfirstexperiencesoftening
followed by stiffening, a behavior widely-known as the snap-through
buckling.
Another important source of nonlinearity stems from the nonlinear
relationship between the stress and strain which has been recognized in
several structural behaviors. Several factors can cause the material
behavior to be nonlinear. The dependency of the material stress-strain
relationontheloadhistory(asinplasticityproblems),loadduration(as
in creep analysis), and temperature (as in thermoplasticity) are some of
thesefactors.
This class of nonlinearity, known as material nonlinearity, can be
idealized to simulate such effects which are pertinent to different
applicationsthroughtheuseofconstitutiverelations.
Aspecialclassofnonlinearproblemsisconcernedwiththechangingnature
of the boundary conditions of the structures involved in the analysis
during motion. This situation is encountered in the analysis of contact
problems.
Pounding of structures, gear-tooth contacts, fitting problems, threaded
connections, and impact bodies are several examples requiring the
evaluationofthecontactboundaries.Theevaluationofcontactboundaries
(nodes,lines,orsurfaces)canbeachievedbyusinggap(contact)elements
betweennodesontheadjacentboundaries.
Yielding of beam-column connections during earthquakes is one of the
applicationsinwhichmaterialnonlinearityareplausible.
THEORYBEHINDNON-LINEARANALYSISAsyouhavelearntfromintroduction,therearethreefactorswhichcause
non-linearity in the body which are elastic behavior of material, large
displacementinbody,andvariationincontact.Intermsofequationthis
canbeexpressedas
[K(D)]{D}={F}
Here,K(D)isstiffnessmatrixwhichisfunctionofdisplacement.
Disthedisplacementmatrix
andFistheForceapplied
So,fromtheaboveequationyoucaneasilyunderstandthatthestiffnessis
changing according to the displacement. Note that displacement is vector
anditalsohasadirection.Ifwecomparethelinearstaticanalysisand
non-linear static analysis curves then we can find out the different
effectsofloadinbothconditions;refertoFigure-1.
Figure-1.StressStraindiagrams
Intermsofloadanddisplacement,thecurveforbothanalysiscanbegiven
byFigure-2.
Figure-2.Loaddisplacementcurve
The normal incremental iteration does not work good for the non-linear
analysis and generate errors as shown in Figure-3. So, Newton-Raphson
algorithmisusedtosolvethenon-linearequation.
Figure-3.Errorinincrementalinterativemethod
TheequationforNewton-Raphsonmethodisgivenas:
[KT]{Δu}={F}-{Fnr}
[KT]=tangentstiffnessmatrix
{Δu}=displacementincrement
{F}=externalloadvector
{Fnr}=internalforcevector
Theiterationcontinuestill{F}-{Fnr}(differencebetweenexternaland
internalloads)iswithinatolerance;refertoFigure-4.
Figure-4.Newton-Raphsonmethod
Thusanonlinearsolutiontypicallyinvolvesthefollowing:
• One or more load steps to apply the external loads and boundary
conditions.(Thisistrueoflinearanalysestoo.)
•Multiplesub-stepstoapplytheloadgradually.Eachsub-steprepresents
oneloadincrement.(Alinearanalysisneedsjustonesub-stepperload
step.)
• Equilibrium iterations to obtain equilibrium (or convergence) at each
sub-step.(Doesnotapplytolinearanalyses.)
RoleofTimeinNon-LinearAnalysisEach load step and sub-step is associated with a value of time. Time in
most nonlinear static analyses is simply used as a counter and does not
meanactual,chronologicaltime.Figure-5showsaload-timecurve.
Figure-5.Loadtimecurve
Bydefault,time=1.0attheendofloadstep1,2.0attheendofload
step 2, and so on. For rate-independent analyses, you can set it to any
desired value for convenience. For example, by setting time equal to the
loadmagnitude,youcaneasilyplottheload-deflectioncurve.
The“timeincrement”betweeneachsub-stepisthetimestepΔt.Timestep
ΔtdeterminestheloadincrementΔFoverasub-step.Thehigherthevalue
ofΔt,thelargertheΔF,soΔthasadirecteffectontheaccuracyofthe
solution.SolidWorksSimulationgivestheflexibilitytouseautomatictime
steppingalgorithmandmanualsettingoftimesteps.
Now, we are going to start with Non-linear Static Analysis which means
thereisnodampingorresistancetotheforce.Notethatthelastexample
in previous chapter, an assembly of wall bracket, was a problem of
Nonlinearstaticanalysisbecausetherewaslargedisplacementinthebody.
Now, we will learn the procedures of SolidWorks Simulation to perform
Nonlinearstaticanalysis.
StartingNonlinearStaticAnalysis•Openthepartonwhichyouwanttoperformtheanalysis.
•ClickontheSolidWorksSimulationbuttonfromtheSOLIDWORKSAdd-Instab of theRibbon to add Simulation tab in the Ribbon, if not addedalready.
•ClickontheDownarrowbelowtheStudyAdvisorbuttonandselecttheNewStudy tool from the drop-down. List of analysis studies that can be
performed,willbedisplayedintheleft.
• Click on the Nonlinear button and then on the Static button from the
Optionsrollout;refertoFigure-6.
Figure-6.StudyPropertyManager
•ClickontheOKbuttonfromthePropertyManager.ThetoolsrelatedtoNon-linearStaticanalysiswillbedisplayed.Notethatmostofthetoolsaresameasdiscussedinpreviouschapters.
ApplyingMaterial•ClickontheApplyMaterialbuttonfromtheRibbon.TheMaterial dialogboxwillbedisplayedasdiscussedinearlierchapters.
•SelecttheAISI1035Steel(SS)optionfromtheleftlistandclickontheApplybutton.
•ClickontheClosebuttonfromthedialogboxtoexit.Thematerialwillbeapplied;refertoFigure-7.
Figure-7.Modelafterapplyingmaterial
ApplyingFixtures•ClickonthedownarrowbelowFixturesAdvisorintheRibbon.Thetoolsrelatedtofixtureswillbedisplayed.
• Click on the Fixed Geometry button from the tool list. The FixturePropertyManagerwillbedisplayed;refertoFigure-8.
Figure-8.FixturePropertyManager
•Selecttheleftflatfacesofthemodel;refertoFigure-9.
Figure-9.Facesfixedforanalysis
• Click on theOK button from the PropertyManager. The holes will befixedasiftheyareboltedatsameposition.
ApplyingTimeVaryingForce• Click on the down arrow below External Loads Advisor button in the
Ribbon.Listofthetoolsrelatedtoloadswillbedisplayed.
•ClickontheForcebuttonfromthelist.TheForce/TorquePropertyManagerwillbedisplayed;refertoFigure-10.
•NotethatVariationwithTimerolloutisaddedinthePropertyManagerandtworadiobuttonsaredisplayednamed,LinearandCurve.OnselectingtheLinearradiobutton,theforcewillgraduallyincreasetillitreachestothe specified force value within the 1 second of time span; refer to
Figure-11.
Figure-10.ForceTorquePropertyManager
Figure-11.Timecurveforlinearvariation
•ClickontheCurveradiobuttonfromtheVariationwithTimerollout.TheEditbuttonwillbecomeactive.
•ClickontheEditbutton.TheTimecurvedialogboxwillbedisplayedasshowninFigure-12.
Figure-12.Timecurvedialogbox
•Clickinthe2ndrowoffirstcolumnandspecifythetimeas20inthe
field.Inthesameway,clickinthe2ndrowofthe2ndcolumnandspecify
theforcevalueas10;refertoFigure-13.
Figure-13.Timecurvedialogboxforcustomization
•ClickontheOKbuttonfromthedialogboxandthenselecttheedgeas
showninFigure-14toapplytheforce.
Figure-14.Edgeselectedforapplyingforce
•ClickontheSelecteddirectionradiobuttonfromtheForce/Torquerollout.Youareaskedtoselectadirectionreference.
•Selectthetopfaceofthemodel;refertoFigure-15.
Figure-15.Faceselectedforforcedirection
•Now,clickonthethirdbuttoni.e.NormaltoPlaneandspecifytheforcevalueas10N;refertoFigure-16.
• Note that if you click on theView button from theVariationwithTimerollout;thegraphwillbedisplayedwiththetotalforceof10x10=100N;refertoFigure-17.
Figure-16.ButtontobeselectedfromForcerollout
Figure-17.Timecurvedialogboxafterentering10inforceeditbox
• Close the dialog box and click on the OK button from the
PropertyManager.Theforcewillbeapplied.
Runningtheanalysis•ClickontheRunbuttonfromtheRibbon.Thesystemwillstartanalyzingtheproblem.Oncethesystemisdone,theresultswillbedisplayedinthe
Modelingarea;refertoFigure-18.NotethatinSolidWorks2015,youcan
alsoseetheintermediateresultsbyselectingthePausebuttonfromtheSolverdialogbox.MakesurethatyouhaveselectedtheShowintermediateresultsuptocurrentstepcheckboxtodisplaytheresults;refertoFigure-19.Ifyoufindthatresultsarenotasperexpectationthenclickonthe
Cancelbuttonandperformthechanges.
Figure-18.Result
Figure-19.Nonlinearanalysissolverdialogbox
Youcaninterprettheresultsasdiscussedinpreviouschapter.
SETTINGPROPERTIESFORNON-LINEAR
STATICANALYSISIt is very important to understand the basic properties of Non-linear
analysisandhowthechangesinpropertiesaffecttheanalysis.Thesteps
belowwilltakeyouthroughvariouspropertysettings.
•AfterstartingNon-linearstaticanalysis,clickontheStudy PropertiestoolfromtheStudyAdvisordrop-downintheRibbon.ThedialogboxwillbedisplayedasshowninFigure-20.
Figure-20.Non-linearstaticanalysispropertiesdialogbox
TheoptionsinSteppingoptions area of the dialog box are used to modifythestarttime,endtime,andincrementalsteps.Forexample,youcancheck
theeffectofloadonacomponentstartingat0secondofloadingtill15
secondafterloading.Also,youwanttochecktheeffectofloadingafter
every3seconds.
•Notethatthestarttimeofanalysisisfixed.Tochangetheendtimefor
analysis,clickintheEndtimeeditboxandchangethevalueasrequired(say15second).
•Tochangethevalueoftimeincrement,selecttheFixedradiobuttonandspecifythedesiredvalueintheeditbox.
•TheoptionsintheGeometricnonlinearityoptionsareaareusedtomodifyoptionsrelatedtogeometricnonlinearity.Therearethreecheckboxesin
this area. Select theUse large displacement formulation check box to usetheformulaoflargedisplacement.Itisimportanttoselectthischeck
box when you that the stiffness matrix will change according to the
loading. Select theUpdate load direction with deflection check box if youwanttocheckthedirectionofdeflectionduringtheloading.Selectthe
Largestrainoptioncheckboxifyouarecheckingthedeflectionofplasticmaterials.
•Selectthedesiredsolverasdiscussedearlier.
•Ifyouwanttousepre-stressesofSolidWorksPlasticsthenclickonthe
In-moldstressestabinthedialogboxandselecttheImportin-moldstressesfromSOLIDWORKSPlasticscheckboxtoactivatetheoption.ClickontheBrowsebuttonandselecttheexportedfileofSolidWorksPlastics.
• Select the Include material from SOLIDWORKS Plastics check box to
include the material of component in current analysis from SolidWorks
Plastics.
•ClickontheOKbuttonfromthedialogboxtoapplysettings.
PERFORMINGNONLINEARSTATICANALYSISONANASSEMBLY
Forperformingnon-linearstaticanalysisonanassembly,weneedtoapply
thecontactsbetweenvariouscomponentsintheassembly.Theprocedureto
performnon-linearanalysisonanassemblyisgivennext.
StartingNon-LinearStaticAnalysis•Openthepartonwhichyouwanttoperformtheanalysis.
•ClickontheSolidWorksSimulationbuttonfromtheSOLIDWORKSAdd-Instab of theRibbon to add Simulation tab in the Ribbon, if not addedalready.
•ClickontheDownarrowbelowtheStudyAdvisorbuttonandselecttheNewStudy tool from the drop-down. List of analysis studies that can be
performed,willbedisplayedintheleft.
• Click on the Nonlinear button and then on the Static button from the
Optionsrollout.
•ClickontheOKbuttonfromthePropertyManager.ThetoolsrelatedtoNon-linearStaticanalysiswillbedisplayed.
ApplyingtheMaterial•ClickontheApplyMaterialbuttonfromtheRibbon.TheMaterial dialogboxwillbedisplayed.
• Select the Alloy Steel material from the left and click on the Applybutton. Note that the elastic properties of material will play an
importantroleintheanalysis.
• Click on the Close button from the dialog box. The material will be
applied.
ApplyingFixtures•ClickonthedownarrowbelowFixturesAdvisorintheRibbon.Thetoolsrelatedtofixtureswillbedisplayed.
• Click on the Fixed Geometry button from the tool list. The FixturePropertyManagerwillbedisplayed.
•SelectthefacesasshowninFigure-21.
Figure-21.Facesselectedforfixing
•ClickontheOKbuttonfromthePropertyManagertofixthefaces.
ApplyingForces• Click on the down arrow below External Loads Advisor button in the
Ribbon.Listofthetoolsrelatedtoloadswillbedisplayed.
•ClickontheForcebuttonfromthelist.TheForce/TorquePropertyManager
willbedisplayed.
•NotethatVariationwithTimerolloutisaddedinthePropertyManagerandtworadiobuttonsaredisplayednamed,LinearandCurve.MakesurethattheLinearradiobuttonisselectedintherollout.
•Enterthevalueofforceas10000NintheForceValueeditbox.•SelectthefaceasshowninFigure-22.
•ClickontheOKbuttonfromthePropertyManagertoapplytheforce.
Figure-22.faceselectedforforce
ApplyingConnections•ExpandtheComponentContactsnodeandright-clickontheGlobalContact(-Bonded-)option;refertoFigure-23.
Figure-23.Optiontobeselected
•SelecttheDeleteoptionfromtheshortcutmenu.TheSimulationdialogboxwillbedisplayed.
•ClickontheYesbuttontodeletethecontact.
•Clickonthe down arrow belowtheConnectionsAdvisor button and selecttheComponentContactbutton;refertoFigure-24.
Figure-24.ComponentContactbutton
• The Component Contact PropertyManager will be displayed as shown in
Figure-25.
Figure-25.ComponentContactPropertyManager
•SelectthetwocomponentsoftheassemblyasshowninFigure-26.
Figure-26.Componentstobeselected
•ClickontheOKbuttonfromthePropertyManager.Thecontactwillbeaddedbetweenthetwocomponents.
•Again,clickonthedownarrowbelowtheConnectionsAdvisorbuttonandclickontheContactSetbutton.TheContactSetsPropertyManagerwillbedisplayedasshowninFigure-27.
Figure-27.ContactSetsPropertyManager
•Selecttheroundfaceofthefirstpartinassembly.
•ClickinthepinkboxintheTyperolloutandselecttheflatfacesoftheblock;refertoFigure-28.
Figure-28.Facesselectedforcontactsets
•SelectthecheckboxnexttoAdvancedrollout.Therolloutwillexpand.
•SelecttheSurfacetosurfaceradiobutton.
•ClickontheOKbuttonfromthePropertyManager.Thecontactswillbeapplied.
Runningtheanalysis•ClickontheRunbuttonfromtheRibbon.Theanalysiswillstart.•Notethatsincethefacesthatweselectedlaterarenotincontactto
eachother,sothedialogboxwiththerelatedmessage;refertoFigure-
29.
Figure-29.NonlinearAnalysisdialogbox
• Click on theNo button from the dialog box since we want to run theanalysis with these conditions only. System will start solving the
analysis.
• On completion of the analysis, the result will be displayed; refer to
Figure-30.
Figure-30.Analysisresult
•Notethatthestressisalsoinducedintheblockbelowthebeambecause
oftheforceinducedonthebeam.
•Youcanchangethecontactbetweenthesurfaceofthebeamandblockto
AllowPenetrationusingtheContactSetsbuttonandcheckfortheresultsforyourinterest.
• To animate any of the result, right-click on the result name from the
AnalysisManager and select theAnimate button from the shortcut menu;refertoFigure-31.
Figure-31.Animatebutton
•Asimulationwillbeplayedforthecurrentselectedresult.
PERFORMINGNONLINEARSTATICANALYSISONARINGUNDERAPPLICATIONOFTORQUE
Themodelusedinthisexampleisaringofcastironundertheloadofa
torque.Thestepstoperformtheanalysisaregivennext.
StartingNon-LinearStaticAnalysis•Openthepartonwhichyouwanttoperformtheanalysis.
•ClickontheSolidWorksSimulationbuttonfromtheSOLIDWORKSAdd-Instab of theRibbon to add Simulation tab in the Ribbon, if not addedalready.
•ClickontheDownarrowbelowtheStudyAdvisorbuttonandselecttheNewStudy tool from the drop-down. List of analysis studies that can be
performed,willbedisplayedintheleft.
• Click on the Nonlinear button and then on the Static button from the
Optionsrollout.
•ClickontheOKbuttonfromthePropertyManager.Thetoolsrelatedto
Non-linearStaticanalysiswillbedisplayed.
ApplyingtheMaterial•ClickontheApplyMaterialbuttonfromtheRibbon.TheMaterial dialogboxwillbedisplayed.
• Select the Alloy Steel material from the left and click on the Applybutton.
• Click on the Close button from the dialog box. The material will be
applied.
ApplyingFixtures•ClickonthedownarrowbelowFixturesAdvisorintheRibbon.Thetoolsrelatedtofixtureswillbedisplayed.
• Click on the Fixed Geometry button from the tool list. The FixturePropertyManagerwillbedisplayed.
•SelectthefacesasshowninFigure-32.ClickontheOKbuttontoapply
fixture.
Figure-32.Faceselectedforfixture
•Sincethisisaroundpartandcandeviatefromitsaxis,soweneedto
restrictmovementofitsaxis.
•ClickagainonthedownarrowbelowtheFixturesAdvisorbuttonandselecttheFixed Hinge button from the tool list. The Fixture PropertyManagerwillbedisplayed;refertoFigure-33.
Figure-33.FixturePropertyManager
•Selecttheinnerroundfaceofthemodeltomakeisfixedhinge;referto
Figure-34.
Figure-34.Roundfaceselectedforfixedhinge
• Click on theOK button from thePropertyManager to create the fixedhinge.
ApplyingForces• Click on the down arrow below External Loads Advisor button in the
Ribbon.Listofthetoolsrelatedtoloadswillbedisplayed.
• Click on the Torque button from the list. The Force/TorquePropertyManagerwillbedisplayed.
•NotethatVariationwithTimerolloutisaddedinthePropertyManagerandtworadiobuttonsaredisplayednamed,LinearandCurve.MakesurethattheLinearradiobuttonisselectedintherollout.
•Enterthevalueofforceas1000NintheForceValueeditbox.•SelectthefaceasshowninFigure-35.
Figure-35.Faceselectedforapplyingtorque
•ClickinthepinkboxinPropertyManagerandselecttheinnerroundfacethatwasselectedforfixedhinge.Previewofthetorquewillbeselected.
• If change of torque direction is required then click on the Reversedirectioncheckbox.ClickontheOKbuttonfromthePropertyManagerto
applythetorque.
Runningtheanalysis•ClickontheRunbuttonfromtheRibbon.Theanalysiswillstart.• After the processing is complete, the results will be displayed in the
modelingarea;refertoFigure-36.
Figure-36.Resultonapplyingtorque
2DSIMPLIFICATION2D Simplification is a method of converting simple 3D models to 2D
geometriessothatanalysiscanbeperformedfaster.Use2DSimplification
optionisavailableforStatic,Non-LinearStatic,Non-LinearDynamic,and
Thermal analysis. In this chapter, we will discuss the Non-Linear Static
analysis using 2D simplification. The same method is also applicable for
otheranalyses. The procedure to perform non-linear static analysis using
2Dsimplificationisgivennext.
StartingNon-LinearStaticAnalysiswith2DSimplification•Openthepartonwhichyouwanttoperformtheanalysis.
•ClickontheSolidWorksSimulationbuttonfromtheSOLIDWORKSAdd-Instab of theRibbon to add Simulation tab in the Ribbon, if not addedalready.
•ClickontheDownarrowbelowtheStudyAdvisorbuttonandselecttheNewStudy tool from the drop-down. List of analysis studies that can be
performed,willbedisplayedintheleft.
• Click on the Nonlinear button and then on the Static button from the
Optionsrollout.
•SelecttheUse2DSimplificationcheckboxfromtheOptionsrollout.
• Click on the OK button from the PropertyManager. The Nonlinear (2DSimplification)PropertyManagerwillbedisplayed;refertoFigure-37.
Figure-37.Nonlinear(2DSimplification)PropertyManager
•TherearefourbuttonsintheStudyTyperolloutofthePropertyManager;PlaneStress,PlaneStrain,ExtrudeandAxi-symmetric.
•SelectthePlaneStressbuttonifyouwanttoanalyzethingeometrieswithonedimensionlargerthantheothers.Notethatthestressactingnormalto
the section plane is assumed as zero or negligible. This button is not
availableforthermalstudy.
•SelectthePlaneStrainbuttonifyouwanttoanalyzewiththickgeometryassumingstrainperpendiculartosectionplaneiszeroornegligible.This
buttonisnotavailableforthermalstudy.
•SelecttheExtrudebuttonifthermalloadisconstantalongtheextrusiondirection.Thisbuttonisavailableforthermalstudyonly.
•SelecttheAxi-symmetricbuttonwhenthegeometry,materialproperties,structural and thermal loads, fixtures, and contact conditions are
symmetric(3600)aboutanaxis.
•IfyouhaveselectedthePlaneStress orPlane Strain button then selectthesectionplaneandenterthedesiredsectiondepth;refertoFigure-38.
If you have selected the Axi-symmetric button then select the section
planeandaxisaboutwhichthepartissymmetric;refertoFigure-39.
Figure-38.2DsimplificationusingPlanestressbutton
Figure-39.2DsimplificationusingAxi-symmetricbutton
•ClickontheOKbuttonfromthePropertyManagerafterselectingdesiredoptions.The2Dsimplifiedgeometryofthemodelwillbedisplayed;refer
toFigure-40.
Figure-40.Axi-symmetric2Dsimplifiedgeometrycreated
ApplyBoundaryConditions•Applymaterial,fixtureandotherboundaryconditionsasrequired;refer
toFigure-41.
Figure-41.Boundaryconditionsfor2Dmodel
InterpretingResults•RuntheanalysisbyusingRunThisStudybutton.Inafewmoments,youwillgettheresultofanalysis;refertoFigure-42.
Figure-42.Resultofanalysison2Dsimplifiedmodel
•Notethattheresultisdisplayedin2Dformbutifyouwanttocheckthe
resultsin3Dthenright-clickonStressresultandselecttheShowas3DPlotoption;refertoFigure-43.
Figure-43.Showas3DPlotoption
Figure-44.Stressplotin3D
PRACTICE1
Check out what happens to the fork under the conditions specified in
Figure-45.Note that the material offorkisAlloySteel and it is in thehandsofanastykid.(Youknowkids!!theydon’texertlinearforces.)
Figure-45.Practice1NonLinearStaticAnalysis
PRACTICE2
Find out the deflection that will occur in the rope if 70 kg load is
applied on the pin in the pulley; refer to Figure-46. Also, analyze the
pulley if 200 kg load is applied on the pin and the rope acts as fixed
steelbar.
Figure-46.Practice2NonLinearAnalysis
SELF-ASSESSMENT
Q1. Which of the following is generally not considered as cause of non-
linearityinNon-linearstaticanalysis?
a.Largedisplacementinbody
b.Non-linearityofmaterial
c.Changingcontactconditions
d.Changeinforce
Q2.Selectthe………….checkboxintheNonlinear-staticPropertiesdialogboxtousetheformulaoflargedisplacement.
Q3. If you want to use pre-stresses of SolidWorks Plastics then click on
the…………..tabintheNonlinear-staticPropertiesdialogbox.
Q4.Theequationforlinearstaticanalysisisgivenas…………..
Q5.TheequationforNewton-RaphsonMethodofnon-linearanalysisisgiven
as………………..
Q6.IncontextofNon-linearanalysis,multiplesub-stepsareusedtoapply
theloadgraduallyandeachsub-steprepresentsoneloadincrement.(T/F)
Q7.Youcanseetheintermediateresultsinnon-linearanalysisifyouhave
selectedtheShowintermediateresultsuptocurrentstepcheckboxintheNonlinearanalysissolverdialogbox.
Non-LinearDynamicAnalysis
Chapter6
TopicsCovered
Themajortopicscoveredinthischapterare:
•Introduction
•StartingNon-LinearDynamicAnalysis.
•UnderstandingIterationtechniquesandIntegrationmethods
•ApplyingMaterial.
•DefiningFixtures
•Applyingloads
•DefiningConnections
•SimulatingAnalysis
•Interpretingresults
•ResponseGraphs
NONLINEARDYNAMICANALYSISInlinearstaticanalysis,theloadsareappliedgraduallyandslowlyuntil
theyreachtheirfullmagnitude.Afterreachingtheirfullmagnitude,the
loadsremainconstant(time-invariant).Theaccelerationsandvelocitiesof
the excited system are negligible, therefore, no inertial and damping
forcesareconsideredintheformulation:
[K]{u}={f}
where:
[K]:stiffnessmatrix
{u}:displacementvector
{f}:loadvector
Thesolutionproducesdisplacements,stresses,thatareconstant.
Inlineardynamicanalysis,theappliedloadsaretime-dependent.Theloads
can be deterministic (periodic, non-periodic), or non-deterministic which
means that they cannot be precisely predicted but they can be described
statistically. The accelerations and velocities of the excited system are
significant,therefore,inertialanddampingforcesshouldbeconsideredin
theformulation:
where:
[K]:stiffnessmatrix
[C]:dampingmatrix
[M]:massmatrix
{u(t)}:timevaryingdisplacementvector
:timevaryingaccelerationvector
:timevaryingvelocityvector
{f(t)}:timevaryingloadvector
Theresponseofthesystemisgivenintermsoftimehistories(amplitudes
versus time), or in terms of frequency spectra (peak values versus
frequency).
Forlineardynamicanalysis,themass,stiffness,anddampingmatricesdo
not vary with time. Can you guess for what type of analysis they change
withthetime?TheanswerisNon-linearDynamicAnalysis.
PreparingPartandStartingNonlinearDynamicAnalysis• Open the Windshield ball.SLDASM file from resource kit on which the
analysisisnotbeperformed.Inthisfile,youwillseeamodelofball
striking to the model of windshield. Note that a major section of
windshieldisnotgoingtoplayroleintheanalysis.Soitisbetterto
removetheextrasectionofwindshieldbyusingthemodelingtools.
•ClickontheExtrudeCuttoolfromtheAssemblyFeaturesdrop-downoftheAssemblyCommandManagerintheRibbon;refertoFigure-1.Youwillbeaskedtoselectthesketchingplane.
Figure-1.ExtrudeCuttool
• Click on the FeatureManager Design Tree button in the left pane and
selecttheTopPlane;refertoFigure-2.ThetoolsforsketchingwillbeactivatedintheSketchCommandManager.PressCTRL+8(notthenumpad)fromthekeyboardtomakethesketchingplaneparalleltoscreen.
Figure-2.SelectingTopplane
• Create a rectangle cutting half of the windshield; refer to Figure-3.
Click on theExit Sketch button at the top-left corner from the SketchCommandManager.
Figure-3.Rectangletobecreated
• Select theThrough All option from theDirection 1 rollout in theCut-Extrude PropertyManager and click on the OK button from the
PropertyManager.ThemodelwillbedisplayedasshowninFigure-4.
•ClickontheSolidWorksSimulationbuttonfromtheSOLIDWORKSAdd-Instab of theRibbon to add Simulation tab in the Ribbon, if not addedalready.
•ClickontheDownarrowbelowtheStudyAdvisorbuttonandselecttheNewStudy tool from the drop-down. List of analysis studies that can be
performed,willbedisplayedintheleft.
•ClickontheNonlinearbuttonandthenontheDynamic button from theOptionsrollout;refertoFigure-5.
Figure-4.Modelafterextrudecut
Figure-5.StudyPropertyManager
•ClickontheOKbuttonfromthePropertyManager.ThetoolsrelatedtoNon-linearDynamicanalysiswillbedisplayed.Notethatmostofthetoolsaresameasdiscussedinpreviouschapters.
WeknowthattheNonlinearDynamicanalysisisstudyofdeformationaswell
askinematics.Here,wehaveanexampleofcarwindshield(madeofAcrylic
plastic)andasteelball;refertoFigure-6.Let’sseewhathappens.(Is
itNationalGeographic’sDestroyedinsecondsornot!!)
Figure-6.Exampleofwindshieldandballstudy
ApplyingMaterial• Right-click onWindshield under theParts category inAnalysisManagerand click on theApply/EditMaterial option from the shortcut menu. TheMaterialdialogboxwillbedisplayed.
•Selectthedesiredmaterial,whichisAcrylic(Medium-highimpact)inthePlastic category from the left list in the dialog box and click on theApplybutton.
•ClickontheClosebuttonfromthedialogboxtoexit.Similarly,applythe Alloy Steel material to ball in the Steel category. The colors of
modelswillbechanged;refertoFigure-7.
Figure-7.Modelafterapplyingmaterial
ApplyingFixtures•ClickonthedownarrowbelowFixturesAdvisorintheRibbon.Thetoolsrelatedtofixtureswillbedisplayed.
• Click on the Fixed Geometry button from the tool list. The FixturePropertyManagerwillbedisplayed;refertoFigure-8.
Figure-8.FixturePropertyManager
•Selecttopandbottomflatfacesofthewindshield;refertoFigure-9.
Figure-9.Facestobefixed
• Click on theOK button from the PropertyManager. The holes will befixedasiftheyareboltedatsomeposition.
ApplyingNoPenetrationContact•Toapplynopenetrationcontactbetweenthecomponents,weneedtoremove
theglobalcontactwhichisbondedbydefault.Todoso,right-clickon
the Component Contacts option from the Connections category in the
AnalysisManager.Ashortcutmenuwillbedisplayed;refertoFigure-10.
Figure-10.Deleteoptionforcontacts
•SelecttheDeleteoptiontodeletethedefaultcontact.Awarningmessagewillbedisplayed.ClickontheYesbuttonfromthedialogbox.
• Click on theContact Set tool from theConnectionsAdvisor drop-down intheRibbon.TheContactSetsPropertyManagerwillbedisplayed.
• Click on the front faces of the Windshield part from the viewport and
thenclickintheselectionboxforsecondset.
•Clickontheroundaceoftheball;refertoFigure-11.
Figure-11.Facesselectedforcontactset
•ClickontheOKbuttonfromthePropertyManagertoapplycontact.
SettingInitialConditions•ClickontheInitialConditiontoolfromtheRibbon.TheInitialConditionsPropertyManagerwillbedisplayed;refertoFigure-12.
Figure-12.InitialConditionsPropertyManager
•SelecttheVelocityradiobuttonfromthePropertyManagertoapplyinitialvelocitytoball.
•ClickontheballpartfromFeatureManagerDesignTreeintheviewport.• Click in the next selection box used for direction and select the Top
planeofassemblyfordirection;refertoFigure-13.
Figure-13.Topplaneselectedfordirectionreference
• Select the Normal to Plane button from the Velocity rollout in the
PropertyManagerandspecifythevalueas5inthecorrespondingeditboxwithReversedirectioncheckboxselected;refertoFigure-14.Notethattocheckthedirectionofforce,youneedtohoverthecursorontheball.
Figure-14.Velocityspecifiedforball
• Click on the OK button from the PropertyManager to apply initial
condition.
GlobalDampingGlobal Damping option is available in all the dynamic analyses in
SolidWorksSimulationsinceweneedtospecifythedampingcoefficientfor
thestudy.Now,assumethatthesystemonwhichwearegoingtoperformthe
studyissubmergedinoil.ToletSolidWorksSimulationunderstandthatour
system is submerged in a kind of oil, we need to specify global damping
matrix.Thestepstodosoaregivennext.
•ClickontheGlobalDampingbuttonfromtheRibbon.TheRayleighdampingPropertyManagerwillbedisplayed;refertoFigure-15.
Figure-15.RayleighdampingPropertyManager
•SpecifythedampingparametersasrequiredandclickontheOKbutton.
Note that for this particular problem, we do not have any damping
conditionsspecifiedsowewillnotapplydamping.
RayleighDampingRayleighdamping has certain mathematical conveniences and is widely used
tomodelinternalstructuraldamping.ThedampingmatrixCisgivenbyC=
αM+βKwhereM,Karethemassandstiffnessmatricesrespectivelyandα,
βareconstantsofproportionality.Oneofthelessattractivefeaturesof
Rayleigh damping is that the achieved damping ratio varies as response
frequencyvaries.Thestiffnessproportionaltermcontributesdampingthat
is linearly proportional to response frequency and the mass proportional
term contributes damping that is inversely proportional to response
frequency.Mathematically,thesefrequencydependenciescanbeseeninthe
formula for damping ratio ξ = π(α/f + βf) where f is the response
frequency.
The plot in Figure-16 illustrates how the separate mass and stiffness
dampingtermscontributetotheoveralldampingratio(Valueofαis0.025
andβis0.023):
Figure-16.DampingratioforRayleighDamping
ApplyingForce
•ClickontheForcetoolfromtheExternalLoadsAdvisordrop-downintheRibbon.TheForce/TorquePropertyManagerwillbedisplayed.
•SelecttheroundfaceofballandtheselecttheSelecteddirection radiobutton from the PropertyManager. The selection box for direction
referencewillbedisplayed.
•SelecttheTopPlaneofassemblyagain.
•ClickontheNormal toPlane button from theForce PropertyManager andspecify the value as 500 in the corresponding edit box with Reversedirectioncheckboxselected;refertoFigure-17.
Figure-17.Forceappliedonball
•ClickontheOKbuttonfromthePropertyManagertoapplytheforce.
Runningtheanalysis•ClickontheRunbuttonfromtheRibbon.Thesystemwillstartanalyzingtheproblem.Oncethesystemisdone,theresultswillbedisplayedinthe
Modelingarea.
Youcaninterprettheresultsasdiscussedinearlierchapters.
SETTINGPARAMETERSINNONLINEARDYNAMICANALYSIS
Asdiscussedinpreviouschapter,themethodtosolvenonlinearequationis
Newton-Raphson method which is applicable for nonlinear dynamic analyses
also. Before we start analyzing the model, we are required to set a few
optionsinPropertiesdialogbox.Theproceduretodosoisgivennext.
•Afterstartingthenonlineardynamicanalysis,clickonStudy Propertiesbutton from the Study Advisor drop-down in the Ribbon. The NonlinearDynamicdialogboxwillbedisplayed;refertoFigure-18.
Most of the options in the dialog box are same as discussed in previous
chapters. We can set the time steps as discussed earlier. Here, we will
discuss the advanced options which have not been discussed in previous
chapters.
Figure-18.Nonlinear-Dynamicdialogbox
•ClickontheAdvancedOptionsbuttonfromthedialogbox.TheAdvancedtabwillbeaddedinthedialogbox;refertoFigure-19.
Figure-19.PartialviewofAdvancedtab
• Click in the Iterative technique drop-down and select the desired
technique. There are two options in the drop-down;Newton-Raphson andModifiedNewton-Raphson.TheNewton-RaphsonmethodsolvesequationuptofirstderivativeoffunctionwhereasmodifiedNewton-Raphsonmethodsolves
equation up to second derivative of function. More details of these
optionsaregiveninnexttopic.
•Clickinthedrop-downfor Integration and select the desired option touse as integration method. There are three options in this drop-down;
Newmark, Wilson-Theta, and Central Difference. The details of these
optionsisgivenafternexttopicinthischapter.
•Settheconvergencetoleranceandstepparametersandthenclickonthe
OKbuttonfromthedialogboxtoapplysettings.
Newton-RaphsonandModifiedN-RMethod
ForNewton-RaphsonMethod:
ForModifiedNewton-RaphsonMethod:
From the equations, we can understand that the Modified Newton-Raphson
methodisfasterformultiplerootequationbecauseittellsslopeaswell
ascurvatureofthefunction.Butforsimplerequationsinwhichweneedto
find out one or two roots it takes more processing than the original
Newton-Raphsonmethod.So,wesuggesttheuseofNewton-Raphsonmethodwhen
youhavesimplerproblemsandforcomplexproblems,youshoulduseModified
Newton-Raphsonmethodasiterativetechnique.
IntegrationMethodAlthoughthereareafewmoreintegrationmethodsbutwewillconcentrate
onthethreemethodsnamedabovesincethesemethodsareusedbySolidWorks
Simulation.
NewmarkMethodNewmark is a type of implicit method for integration which means
differential equations are combined with equations of motions and the
displacementsarecalculatedbydirectlysolvingtheequation.TheNewmark
method also assumes that the acceleration varies linearly between two
instants of time. The equation for velocity and displacement in Newmark
methodcanbegivenbyFigure-20.
Figure-20.EquationforNewmarkBetamethod
Theparametersalphaandbetaareuser-definedandcanbechangedtosuit
therequirementsofparticularproblems.Forexample,puttingα=1/2andβ
=0makestheaccelerationconstantandequaltoẌt.Weknowtheequationof
forceas,
Here[M]ismassmatrixand{Ft+Δt
}isforcematrix
TheEquationsforMassandForcecanbegivenby,
SomeoftheimportantpointsforusingNewmarkbetamethodare:
•InNewmarkmethod,theamplitudeinlinearsystemsisconservedandthe
responseisunconditionallystableif
and
• If alpha = 1/2 and beta = 1/4 then large truncation errors occur in
frequencyofresponse.
•Ifbeta=1/2thenspuriousdampingisintroducedproportionalto(alpha-
1/2).
• If beta is negative then self-excited vibrations arouse and if beta is
greaterthan1/2,apositivedampingisintroduced.
Instraightwords,theselectionofalphaandbetacanmakebigdifference
inresultsofanalysissotheirvalueshouldbedecidedverycarefully.
AlgorithmbasedonNewmarkmethoda.InitialComputations:
1.Formstiffness[K],mass[M],anddamping[C]matrices.
2.Initialize{X0},{Ẋ
0},and{Ẍ
0}.
3. Select the time step Δt, parameters α and β and calculate integration
constants,β≥0.5andα≥0.25(0.5+β)2.
4.Formeffectivestiffnessmatrix:
5.Triangularize
b.ForEachtimestep,calculate:
Wilson-ThetaMethodWilson-Thetamethodisalsoatypeofimplicitmethodforintegration.It
assumes that the acceleration of system varies linearly between two
instants of time ti=iΔt to t
i+θΔt, where θ≥1.0. If τ is time increment
betweentandt+θΔtthenaccelarationisgivenas,
Onsuccessiveintegration,displacementisgivenby,
Puttingvaluesinforceequationweget,
SomeoftheimportantpointsforusingWilsonthetamethodare:
•Whenθ=0thenmethodreducestolinearaccelerationscheme.
•Themethodisunconditionallystableforθ≥1.37.
• A value of θ=1.4 is used for nonlinear dynamic systems which is our
currentstudycase.
• In this method, there is no need to specify initial conditions because
thedisplacement,velocity,andaccelerationarefunctionsoftime.
CentralDifferenceMethodCentral Difference method is a type of explicit method for integration
which means the response quantities are expressed in terms of previously
determined values of displacement, velocity, and acceleration. It is
assumedthatthetimeperiodisdividedintonequalpartsofinterval.The
accuracyofsolutiondependsonsizeoftimestep.Thecriticaltimestep
is given by Δtcri = τ
n/Π, where τ
n is natural period of system. If Δt is
selected larger than Δtcri then method becomes unstable making dynamic
analysis meaningless due to big error. The equation of force for central
differencemethodisgivenby,
Onsolvingfordisplacement,weget
Fromtheequation,youcaneasilyinterpretthatthedisplacementofmass
Xi+1canbecalculatedonlyifyouhavevalueofX
i,X
i-1andpresentforceF
i.
ButinitialconditionsprovideonlyX0andẊ
0 so X
-1 is calculated to find
outX1.FirsttheaccelerationẌ
0iscalculatedandthenthevalueofX
-1is
calculatedbyusingitasgivennext,
NotethatthetimestepshouldbelessthanΔtcriforusingofthismethod
otherwisetheresultswillnotbemeaningful.
PRACTICAL1
In this practical, we will find out response curve of the model under
conditionsgiveninFigure-21.
Figure-21.Practical1nonlineardynamic
StartingNonlinearDynamicAnalysis•Openthepartonwhichyouwanttoperformtheanalysis.
•ClickontheSolidWorksSimulationbuttonfromtheSOLIDWORKSAdd-Instab of theRibbon to add Simulation tab in the Ribbon, if not addedalready.
•ClickontheDownarrowbelowtheStudyAdvisorbuttonandselecttheNewStudy tool from the drop-down. List of analysis studies that can be
performed,willbedisplayedintheleft.
•ClickontheNonlinearbuttonandthenontheDynamic button from theOptionsrollout;refertoFigure-22.
Figure-22.StudyPropertyManager
•ClickontheOKbuttonfromthePropertyManager.ThetoolsrelatedtoNon-linearDynamicanalysiswillbedisplayed.Notethatmostofthetoolsaresameasdiscussedinpreviouschapters.
• Select the desired method and integration technique for analysis. For
this practical, we have used Newton-Raphson method with Newmark
integrationtechnique.
ApplyingMaterial•ClickontheApplyMaterialbuttonfromtheRibbon.TheMaterial dialogboxwillbedisplayedasdiscussedinearlierchapters.
•Selectthedesiredmaterial,sayAlloySteeloptionfromtheleftlistandclickontheApplybutton.
•ClickontheClosebuttonfromthedialogboxtoexit.Thecolorofmodelwillbechanged;refertoFigure-23.
Figure-23.Modelafterapplyingmaterial
ApplyingTimeVaryingTorque• Click on the down arrow below External Loads Advisor button in the
Ribbon.Listofthetoolsrelatedtoloadswillbedisplayed.
• Click on the Torque button from the list. The Force/TorquePropertyManagerwillbedisplayed.
•Selecttheroundfaceofthemodelandspecifythetorquevalueasshown
inFigure-24.
Figure-24.Torquevaluespecified
•ExpandtheVariationwithTimerolloutinthePropertyManagerandclickontheCurveradiobuttontodefinetheloadingcurve.
•ClickontheEditbuttonfromtheVariationwithTimerolloutanddefinethetimecurveasshowninFigure-25.Notethattoaddanewrowinthe
table,youneedtodouble-clickonthelastfieldunderPointscolumninthetable.
Figure-25.TimeCurvefortorque
•ClickontheOKbuttonfromthedialogboxandthenOKbuttonfromthe
PropertyManager.
ApplyingFixtures•ClickonthedownarrowbelowFixturesAdvisorintheRibbon.Thetoolsrelatedtofixtureswillbedisplayed.
• Click on the Fixed Geometry button from the tool list. The FixturePropertyManagerwillbedisplayed.
•SelecttheholescutfromthemodelasshowninFigure-26.
Figure-26.Holesfixed
•ClickontheOKbuttonfromthePropertyManagertoapplythefixtures.
ApplyingDamping•ClickontheGlobalDampingbuttonfromtheRibbon.TheRayleighdampingPropertyManagerwillbedisplayed.
•Specifythevalueofalphaas2.5inthecorrespondingeditboxandthenclickontheOKbuttonfromthePropertyManager.
Specifyinginitialvelocity• Click on the Initial Conditions button from the Ribbon. The InitialConditionsPropertyManagerwillbedisplayed;refertoFigure-27.
Figure-27.InitialConditionsPropertyManager
•ClickontheVelocityradiobuttonandselecttheroundfaceofthemodel.
• Click in the pink selection box of PropertyManager to define the
direction and then select the round face of the model again; refer to
Figure-28.
Figure-28.Faceselectedfordefiningvelocity
•SelecttheCircumferentialbuttonfromtheVelocityrolloutandspecifythevalueas30inthecorrespondingeditbox;refertoFigure-29.
Figure-29.Circumferentialvelocitydefined
•ClickontheOKbuttonfromthePropertyManager.
DefiningMeshSinceweareperformingtheanalysisforeducationalpurposeonly,herewe
will define the mesh as coarse. This will reduce the solving time of
analysis.
•ClickonthedownarrowbelowRunThisStudybuttonintheRibbon.Listoftoolswillbedisplayed.
•ClickontheCreateMeshtoolfromthelist.TheMeshPropertyManagerwillbedisplayed.
• Move the slider to extreme left in the Mesh Density rollout in
PropertyManager;refertoFigure-30.
Figure-30.Coarsemeshdensity
•ClickontheOKbuttonfromthePropertyManagertoapplymeshing.
Runninganalysis• Click on theRun This Study button from theRibbon. The intermediateresultsofanalysiswillbedisplayed;refertoFigure-31.Notethatthe
intermediate results display is latest enhancement in SolidWorks
Simulation.
Figure-31.Runningnonlinearanalysis
CreatingTimeresponsecurveAsdiscussedearlier,TimeresponsecurveisthemainresultforanyNon-
linearanalysisbecausestresschangesaspertheforcecurve.Itmightbe
possiblethatthestressisverylowattheendofstudybutveryhighin
the middle of study. So, Time response curve gives the real time
informationofstresswithrespecttotime.ThestepstoaddTimeresponse
curveinresults,aregivennext.
•Right-clickontheResultnodeintheAnalysisManager.Ashort-cutmenuwillbedisplayed;refertoFigure-32.
Figure-32.ShortcutmenuforTimeresponsecurve
•ClickontheDefineTimeHistoryPlotoptionfromtheshortcutmenu.TheTimeHistoryGraphPropertyManagerwillbedisplayed;refertoFigure-33.
• Make sure thatTime is selected in theX axis drop-down and Stress isselectedintheYaxisdrop-downasshowninFigure-33.
Figure-33.TimeHistoryGraphPropertyManager
• Click on theOK button from thePropertyManager. TheResponseGraphwill be displayed; refer to Figure-34. Note that this is the response
graph of node 1 which was selected in the Time History GraphPropertyManagerearlier;refertopreviosfigure(Figure-33).
Figure-34.ResponseGraph
•ClosetheResponseGraphdialogboxandright-clickonResponse1resultintheResultnodeinAnalysisManager;refertoFigure-35.
Figure-35.Shortcutmenuforresponseresult
• Select the Edit Definition option from the shortcut menu and select a
differentnodetochecktheresponse.Like,selectthenode95(Figure-36)
fromthelistandclickOKfromthePropertyManagertoseetheresponsegraph(Figure-37).
Figure-36.Node95
Figure-37.ResponseGraphfornode95
• In this way, you can check the response graph of critical areas. Note
that the stress of this node has gone up to 1.566x108 but in Stress1
result,wedon’tfindanyspotwithsuchhighstress;refertoFigure-38.
So,youcannowunderstandwhyResponsegraphisimportantincaseofnon-
linearanalyses.
Figure-38.Comparingstressresults
PRACTICE1
A sheet metal plate of 140mmX40mmX3mm is placed on bending machine
withbendinglineatthecenterofplatealonglength.Theloadappliedby
bendingmachineonplateis100kgf.Findoutifplatewillbendornot.
SELF-ASSESSMENT
Q1.Forlineardynamicanalysis,themass,stiffness,anddampingmatrices
donotvarywithtime.(T/F)
Q2.GlobalDampingoptionisnotavailableinalltypeofdynamicanalyses
inSolidWorksSimulation.(T/F)
Q3.CentralDifferencemethodisatypeofexplicitmethodofintegration.
(T/F)
Q4.InaNon-linearanalysisstresschangesaspertheforcecurve.(T/F)
Q5. Which of the following condition is required for stable solution of
NewmarkIntegrationMethod?
a.α≥0.5andβ≥0.25(α+0.5)2
b.α≤0.5andβ≥0.25(α+0.5)2
c.α≥0.5andβ≤0.25(α+0.5)2
d.α≤0.5andβ≤0.25(α+0.5)2
Q6.Inallcases,theModifiedNewton-Raphsonmethodisfasterbecauseit
tellsslopeaswellascurvatureofthefunction.(T/F)
Q7. Newmark is a type of implicit method for integration which means
differential equations are combined with equations of motions and the
displacementsarecalculatedbydirectlysolvingtheequation.(T/F)
FrequencyAnalysis
Chapter7
TopicsCovered
Themajortopicscoveredinthischapterare:
•Introduction
•StartingFrequencyAnalysis.
•ApplyingMaterial.
•DefiningFixtures
•Applyingloads
•DefiningConnections
•SimulatingAnalysis.
•Interpretingresults
INTRODUCTIONEverystructurehasthetendencytovibrateatcertainfrequencies,called
natural or resonant frequencies.Eachnaturalfrequencyisassociatedwithacertain shape, called mode shape, that the model tends to assume when
vibratingatthatfrequency.
When a structure is properly excited by a dynamic load with a frequency
thatcoincideswithoneofitsnaturalfrequencies,thestructureundergoes
large displacements and stresses. This phenomenon is known as resonance.For undamped systems, resonance theoretically causes infinite motion.
Damping,however,putsalimitontheresponseofthestructuresduetoresonantloads.
A real model has an infinite number of natural frequencies. However, a
finite element model has a finite number of natural frequencies that are
equaltothenumberofdegreesoffreedomconsideredinthemodel.Onlythe
firstfewmodesareneededformostpurposes.
Ifyourdesignissubjectedtodynamicenvironments,staticstudiescannot
be used to evaluate the response. Frequency studies can help you design
vibration isolation systems by avoiding resonance in specific frequency
band. They also form the basis for evaluating the response of linear
dynamicsystemswheretheresponseofasystemtoadynamicenvironmentis
assumed to be equal to the summation of the contributions of the modes
consideredintheanalysis.
Notethatresonanceisdesirableinthedesignofsomedevices.Forexample,resonanceisrequiredinguitarsandviolins.
The natural frequencies and corresponding mode shapes depend on the
geometry, material properties, and support conditions. The computation of
natural frequencies and mode shapes is known as modal, frequency, and
normalmodeanalysis.
Whenbuildingthegeometryofamodel,youusuallycreateitbasedonthe
original(undeformed)shapeofthemodel.Someloads,likethestructure’s
own weight, are always present and can cause considerable effects on the
shapeofthestructureanditsmodalproperties.Inmanycases,thiseffect
canbeignoredbecausetheinduceddeflectionsaresmall.
Loadsaffectthemodalcharacteristicsofabody.Ingeneral,compressive
loads decrease resonant frequencies and tensile loads increase them. This
factiseasilydemonstratedbychangingthetensiononaviolinstring.The
higherthetension,thehigherthefrequency(tone).
You do not need to define any loads for a frequency study but if you do
theireffectwillbeconsidered.Byhavingevaluatednaturalfrequenciesof
a structure’s vibrations at the design stage, you can optimize the
structurewiththegoalofmeetingthefrequencyvibro-stabilitycondition.
To increase natural frequencies, you would need to add rigidity to the
structureand(or)reduceitsweight.Forexample,inthecaseofaslender
object,therigiditycanbeincreasedbyreducingthelengthandincreasing
the thickness of the object. To reduce a part’s natural frequency, you
should, on the contrary, increase the weight or reduce the object’s
rigidity.
Note that the software also considers thermal and fluid pressure effects
forfrequencystudies.
Theproceduretoperformthefrequencyanalysisisgivennext.
STARTINGFREQUENCYANALYSIS•Openthepartonwhichyouwanttoperformtheanalysis.
•ClickontheSolidWorksSimulationbuttonfromtheSOLIDWORKSAdd-Instab of theRibbon to add Simulation tab in the Ribbon, if not addedalready.
•ClickontheDownarrowbelowtheStudyAdvisorbuttonandselecttheNewStudy tool from the drop-down. List of analysis studies that can be
performed,willbedisplayedintheleft.
• Click on the Frequency button then click on theOK button from the
PropertyManager. The tools related to frequency analysis will be
displayed.
ApplyingMaterial•ClickontheApplyMaterialbuttonfromtheRibbon.TheMaterial dialogboxwillbedisplayed.
•ExpandtheSolidWorksMaterialsnodeandthentheAluminiumAlloysnodeintheleftofthedialogbox.
•BrowsethroughthematerialsandselecttheAluminamaterial.
• Click on theApply button and then click on theClose button from thedialogboxtoexitthedialogbox.
ApplyingFixtures
•ClickonthedownarrowbelowFixturesAdvisorintheRibbon.Thetoolsrelatedtofixtureswillbedisplayed.
• Click on the Fixed Geometry button from the tool list. The FixturePropertyManagerwillbedisplayed.
•SelectthefaceofthemodelasshowninFigure-1.
•ClickontheOKbuttonfromthePropertyManager.
Figure-1.Faceforfixture
ApplyingForcesNotethatitisnotnecessarytoapplyforcesforperformingtheFrequency
analysisbutifyouapplytheforces,theyarecountedfortheireffectsin
deformation.Theydonotmakeanyeffectonresonancefrequencies.
•ClickonthedownarrowbelowExternalLoadsAdvisorfromtheRibbon.Thelistoftoolswillbedisplayed.
• Click on the Force button from the list. The Force/TorquePropertyManagerwillbedisplayed;refertoFigure-2.
Figure-2.ForceTorquePropertyManager
•SelectthefaceasshowninFigure-3.andspecifytheforcevalueas100
N.
Figure-3.Forcetobeapplied
•ClickontheOKbuttonfromthePropertyManager.
SettingParametersfortheanalysis•Right-clickonthenameofanalysisintheAnalysisManager.Ashortcutmenuwillbedisplayed;refertoFigure-4.
Figure-4.Shortcutmenuforproperties
• Click on the Properties button from the shortcut menu. The Frequencydialogboxwillbedisplayed;refertoFigure-5.
•Inthisdialogbox,theNumberoffrequenciesspinnerisusedtospecifythenumberofnaturalfrequenciesthataretobefoundout.
•Ifyouwanttocheckthenaturalfrequencyclosertoaspecificfrequency
then select theCalculate frequencies closest to: (Frequency Shift) check boxandspecifythevalueoffrequencyintheadjacenteditbox.
•AsweareapplyingforcewithintheFrequencyanalysis,thenweneedto
select theDirect sparse Solver from the Solver area in the dialog box.Otherwise,anerrorwillbegenerated.
Figure-5.Frequencydialogbox
•Otheroptionsinthedialogboxhavealreadybeendiscussed.
•ClickontheOKbuttonfromthedialogbox.
Runningtheanalysis•ClickontheRunbuttonfromtheRibbontoruntheanalysis.Thesolvingprocessofanalysiswillstart.
• After the process is complete, the results will be displayed; refer to
Figure-6.
Figure-6.ResultofFrequencyanalysis
•TherearesixnodesdisplayedunderResultsintheAnalysisManagerwhichrepresentsixmodeshapesatrespectivenaturalfrequencies.
• From the results, you find that our part should not be working in the
rangeofthenaturalfrequencieslisted.
•Todisplaythelistofresonantfrequencies,right-clickontheResultsnodeintheAnalysisManager.Ashortcutmenuwillbedisplayed.
•ClickontheListResonantFrequenciesbuttonfromtheshortcutmenu;refertoFigure-7.
Figure-7.Shortcutmenuforresults
• TheListModes dialog box will be displayed. TheFrequency (Hz) columnshowstheresonantfrequencies;refertoFigure-8.
Figure-8.ListModesdialogbox
SELF-ASSESSMENT
Q1. Every structure has the tendency to vibrate at certain frequencies,
called…………..or…………frequencies.
Q2.Eachnaturalfrequencyisassociatedwithacertainshape,called……………
Q3.Thestructureundergoeslargedisplacementsandstressesundertheload
with frequencies coinciding with its natural frequencies. This phenomenon
isknownas…………….
Q4. Frequency studies can help you design vibration isolation systems by
avoidingresonanceinspecificfrequencyband.(T/F)
Q5.Toincreaseapart’snaturalfrequency,youshouldincreasetheweight
orreducetheobject’srigidity.(T/F)
Q6. For undamped systems, resonance theoretically causes infinite motion.
(T/F)
Q7.Arealmodelhasaninfinitenumberofnaturalfrequencies.(T/F)
Q8. ………… analysis can help you design vibration isolation systems by
avoidingresonanceinspecificfrequencyband.
LinearDynamicAnalysis
Chapter8
TopicsCovered
Themajortopicscoveredinthischapterare:
•Introduction
•TypesofLinearDynamicAnalysis
•StartingLinearDynamicAnalysis.
•ApplyingMaterial.
•DefiningFixtures
•Applyingloads
•DefiningConnections
•SimulatingAnalysis.
•Interpretingresults
LINEARDYNAMICANALYSISStaticstudiesassumethatloadsareconstantorappliedveryslowlyuntil
theyreachtheirfullvalues.Becauseofthisassumption,thevelocityand
acceleration of each particle of the model is assumed to be zero. As a
result,staticstudiesneglectinertialanddampingforces.
Formanypracticalcases,loadsarenotappliedslowlyortheychangewith
time or frequency. For such cases, use a dynamic study. Generally if the
frequency of a load is larger than 1/3 of the lowest (fundamental)
frequency,adynamicstudyshouldbeused.
Linear dynamic studies are based on frequency studies. The software
calculates the response of the model by accumulating the contribution of
eachmodetotheloadingenvironment.Inmostcases,onlythelowermodes
contribute significantly to the response. The contribution of a mode
depends on the load’s frequency content, magnitude, direction, duration,
andlocation.
Objectivesofadynamicanalysis• Design structural and mechanical systems to perform without failure in
dynamicenvironments.
• Modify system’s characteristics (i.e. geometry, damping mechanisms,
materialproperties,etc.)toreducevibrationeffects.
TherearefourtypeofdynamicanalysesthatcanbeperformedinSolidWorks
Simulation:
•ModalTimeHistoryAnalysis
•HarmonicAnalysis
•RandomVibrationAnalysis
•ResponseSpectrumAnalysis
Beforewestartknowingaboutvariousdynamicanalyses,itisimportantto
understandtheconceptofdamping.
DampingIf you apply initial conditions to a dynamic system, the system vibrates
with decreasing amplitudes until it comes to rest. This phenomenon is
calleddamping.Dampingisacomplexphenomenonthatdissipatesenergyby
many mechanisms like internal and external friction, thermal effects of
cyclic elastic straining materials at the microscopic level, and air
resistance.
Itisdifficulttodescribedissipationmechanismsmathematically.Damping
effectsareusuallyrepresentedbyidealizedmathematicalformulations.For
manycases,dampingeffectsareadequatelydescribedbyequivalentviscous
dampers.
A viscous damper (or dashpot) generates a force that is proportional to
velocity. A piston that can move freely inside a cylinder filled with a
viscousfluidlikeoilisanexampleofaviscousdamper.
Thefollowingtypesofdampingareavailable:
ModalDamping
RayleighDamping
CompositeModalDamping
Concentrated Dampers. Defined between two locations (available for modal
timehistoryanalysis).
WehavediscussedaboutRayleighDampinginpreviouschapters.Now,wewill
discussabouttheotherdampingoptions.
ModalDampingModal damping is defined as a ratio of the critical damping C
c for each
mode. Critical damping Cc is the least amount of damping that causes a
systemtoreturntoitsequilibriumpositionwithoutoscillating.
The modal damping ratio can be determined accurately with proper field
tests. The ratio varies from 0.01 for lightly damped systems to 0.15 or
moreforhighlydampedsystems.
Whenexperimentaldataisnotavailable,usedatafromasimilarclassof
systems to determine the damping properties. Smaller ratios are more
conservative since higher ratios reduce vibration amplitudes. In general,
neglecting damping leads to a conservative estimate of the system’s
response.
Inmathematicalterms,dampingratioisgivenby
Here,Cc=2mω
n
Dampingratiosfordifferentsystemsandmaterialsaregivenas:
CompositeModalDampingCompositemodaldampingallowsthedefinitionofthedampingasamaterial
property. Material damping ratio is defined in the Properties tab of theMaterialdialogbox.Theprogramusesthispropertytocalculateequivalentmodaldampingratioforeachmode.
Thecompositemodaldampingisdefinedintermsofequivalentmodaldamping
ratiosas:
βj={φ}
j
T {φ}j
where:
βj=equivalentmodaldampingratioofthejthmode
{φ}j
T=jthnormalizedmodaleigenvector
= modified global mass matrix constructed from the product of the
element’sdampingcoefficientanditsmassmatrix.
Here,thequestionsrise:WheretouseModaldamping?WheretouseRayleighDamping?WhytheCompositeModaldampingisrequired?
The answer to these questions are not straight forward but they are
dependentofmanyfactorslikematerialstructure,massproperties,damping
systemused,andmanyotherpropertiesofthesystem.
•RayleighDampingschemeallowsusetheflexibilityofusingsystemsthat
change damping force depending on mass matrix and stiffness matrix of
model. If you expect changes to happen in mass or stiffness then you
should use Rayleigh Damping scheme otherwise it is good to use Modal
dampingschemebecauseyouhaveadirectvalueofdampingformostofthe
materials.
• If there is requirement of calculating internal damping of part then
ModaldampingschemeisbetterthanRayleighdampingscheme.
• If the part has softer elements then Rayleigh Damping can product
unrealisticresultsbecauseofstiffnessmatrixpart.So,youshoulduse
Modaldamping.
The Composite Modal Damping uses the damping value specified in the
materialproperties.Inthisway,itreducestherequirementofexplicitly
definingdampingvalueforeachobjectinassemblyunderthestudy.
TYPESOFDYNAMICANALYSISOnthebasisoftheuse,theallfouranalysescanbeexplainedasfollows:
ModalTimeHistoryAnalysisUsemodaltimehistoryanalysiswhenthevariationofeachloadwithtime
isknownexplicitlyandyouareinterestedintheresponseasafunctionof
time.
Typicalloadsinclude:
•Shock(orpulse)loads
•Generaltime-varyingloads(periodicornon-periodic)
• Uniform base motion (displacement, velocity, or acceleration applied to
allsupports)
• Support motions (displacement, velocity, or acceleration applied to
selectedsupportsnon-uniformly)
• Initial conditions (a finite displacement, velocity, or acceleration
appliedtoapartorthewholemodelattimet=0).
Thesolutionoftheequationsofmotionformultidegree-of-freedomsystems
incorporatesModalanalysistechniques.
Thesolution’saccuracycanimprovebyusingasmallertimestep.
After running the study, you can view displacements, stresses, strains,
reactionforces,etc.atdifferenttimesteps,oryoucangraphresultsat
specified locations versus time. If no locations are specified in Result
Options,resultsatallnodesaresaved.
Modal, Rayleigh, composite modal, and concentrated dampers are available
formodaltimehistoryanalysis.
HarmonicAnalysisUse harmonic analysis to calculate the peak steady state response due to
harmonicloadsorbaseexcitations.
A harmonic load P is expressed as P = A sin (ωt + φ) where: A is the
amplitude,ωisthefrequency,tistime,andφisthephaseangle.Sample
harmonicloadsofdifferentfrequencieswversustimeareshowninFigure-
1.
Figure-1.Graphforlineardynamicanalysis
Although you can create a modal time history study and define loads as
functionsoftime,youmaynotbeinterestedinthetransientvariationof
the response with time. In such cases, you save time and resources by
solving for the steady-state peak response at the desired operational
frequencyrangeusingharmonicanalysis.
For example, a motor mounted on a test table transfers harmonic loads to
thesupportsystemthroughthebolts.Youcanmodelthesupportingsystem
and define a harmonic study to evaluate the steady-state peak
displacements, stresses, etc. for the motor’s range of operating
frequencies.Youcanapproximatethemotorbyadistributedmass.
After running the study, you can view peak stresses, displacements,
accelerations,andvelocitiesaswellasphaseanglesoftheresponseover
therangeofoperatingfrequencies.
Modal,Rayleigh,andCompositemodaldampingoptionsareavailableforthis
typeofanalysis.
RandomVibrationAnalysisUse a random vibration study to calculate the response due to non-
deterministicloads.Examplesofnon-deterministicloadsinclude:
•Loadsgeneratedonawheelofacartravelingonaroughroad
•Baseaccelerationsgeneratedbyearthquakes
•Pressuregeneratedbyairturbulence
•Pressurefromseawavesorstrongwind
In a random vibration study, loads are described statistically by power
spectral density (psd) functions. The units of psd are the units of the
load squared over frequency as a function of frequency. For example, the
unitsofapsdcurveforpressureare(psi)2/Hz.
The solution of random vibration problems is formulated in the frequency
domain.
Afterrunningthestudy,youcanplotroot-mean-square(RMS)values,orpsd
results of stresses, displacements, velocities, etc. at a specific
frequencyorgraphresultsatspecificlocationsversusfrequencyvalues.
Modal,Rayleigh,andCompositemodaldampingoptionsareavailableforthis
typeofanalysis.
ResponseSpectrumAnalysisInaresponsespectrumanalysis,theresultsofamodalanalysisareused
intermsofaknownspectrumtocalculatedisplacementsandstressesinthe
model.Foreachmode,aresponseisreadfromadesignspectrumbasedon
themodalfrequencyandagivendampingratio.Allmodalresponsesarethen
combinedtoprovideanestimateofthetotalresponseofthestructure.
You can use a response spectrum analysis rather than a time history
analysistoestimatetheresponseofstructurestorandomortime-dependent
loadingenvironmentssuchasearthquakes,windloads,oceanwaveloads,jet
enginethrustorrocketmotorvibrations.
After reading from the above section, we can find that the pattern of forceapplicationchangesinalltheanalyses.Now,wewillstartwiththeRandomVibrationAnalysisandproceedtootherDynamicanalyses.
StartingRandomVibrationAnalysis•Openthepartonwhichyouwanttoperformtheanalysis.
•ClickontheSolidWorksSimulationbuttonfromtheSOLIDWORKSAdd-Instab of theRibbon to add Simulation tab in the Ribbon, if not addedalready.
•ClickontheDownarrowbelowtheStudyAdvisorbuttonandselecttheNew
Study tool from the drop-down. List of analysis studies that can be
performed,willbedisplayedintheleft.
• Click on the Linear Dynamic button and then on the Random VibrationAnalysisbuttonfromtheOptionsrollout;refertoFigure-2.
Figure-2.StudyPropertyManager
•ClickontheOKbuttonfromthePropertyManager.ThetoolsrelatedtoLinear Dynamic Random Vibration analysis will be displayed. Note thatmostofthetoolsaresameasdiscussedinpreviouschapters.
ApplyingMaterial•ClickontheApplyMaterialbuttonfromtheRibbon.TheMaterial dialogboxwillbedisplayedasdiscussedinearlierchapters.
•SelecttheAlloySteeloptionfromtheleftlistandclickontheApplybutton.
•ClickontheClosebuttonfromthedialogboxtoexit.Thecolorofmodelwillbechanged;refertoFigure-3.
Figure-3.Modelafterapplyingmaterial
ApplyingFixtures•ClickonthedownarrowbelowFixturesAdvisorintheRibbon.Thetoolsrelatedtofixtureswillbedisplayed.
• Click on the Fixed Geometry button from the tool list. The FixturePropertyManagerwillbedisplayed.
•Selecttheroundfacesofthemodel;refertoFigure-4.
Figure-4.Facestobefixed
•ClickontheOKbuttonfromthePropertyManager.Theroundfaceswillbefixedasiftheyareboltedatthatposition.
ApplyingForceVibrations• Click on the down arrow below External Loads Advisor button in the
Ribbon.Listofthetoolsrelatedtoloadswillbedisplayed.
•ClickontheForcebuttonfromthelist.TheForce/TorquePropertyManagerwillbedisplayed.
•ClickintheForceValueeditboxinForce/Torquerolloutandspecifythevalueas5000.
•SelectthefaceofthemodelasshowninFigure-5.
Figure-5.Faceofmodeltobeselected
•ClickontheOKbuttonfromthePropertyManager.
ApplyingGlobalDamping•ClickontheGlobalDamping button in theRibbon. TheGlobalDampingPropertyManagerwillbedisplayed;refertoFigure-6.
Figure-6.GlobalDampingPropertyManager
•SpecifythemodaldampingratiointhecellunderDampingRatioscolumnin the table or click on theRayleigh damping radio button and specifythedesiredparametersintheeditboxesdisplayed.
•ClickontheOKbuttonfromthePropertyManager.
Runningtheanalysis•ClickontheRunbuttonfromtheRibbon.Thesystemwillstartanalyzingtheproblem.Oncethesystemisdone,theresultswillbedisplayedinthe
Modelingarea;refertoFigure-7.
Figure-7.Result
•YoumayneedtodeselecttheDeformedResultbuttonfromtheRibbontocheckthenon-deformedresult;refertoFigure-8.
Figure-8.DeformedResultbutton
Youcaninterprettheresultsasdiscussedinearlierchapters.
MODALTIMEHISTORYANALYSISAsdiscussedearlier,ModalTimeHistoryanalysisisdonewhenyouknowthe
variationofloadwithrespecttotimeexplicitly.NotethatTimehasgood
relationwithFrequencywhichisFrequency=1/Time.So,wecandefinethe
changingloadwithrespecttotimeorFrequency.Theproceduretoperform
thisanalysisisgivennext.
Assumethatthereisaboltmountedonenginechamber.Now,youknowthatenginehaslittlebitteasingnaturewhenitisstarted.So,theforceexertedonboltisvaryingwithtime.ThecompleteparametersofstudyaregiveninFigure-9.WeneedtofindouttheStressinducedinthebolt.
Figure-9.ParametersforModalTimeHistorystudy
StartingModalTimeHistoryAnalysis•Openthepartonwhichyouwanttoperformtheanalysis.
•ClickontheSolidWorksSimulationbuttonfromtheSOLIDWORKSAdd-Instab of theRibbon to add Simulation tab in the Ribbon, if not addedalready.
•ClickontheDownarrowbelowtheStudyAdvisorbuttonandselecttheNewStudy tool from the drop-down. List of analysis studies that can be
performed,willbedisplayedintheleft.
• Click on theLinearDynamic button and then on theModalTimeHistorybuttonfromtheOptionsrollout;refertoFigure-10.
Figure-10.ModalTimeHistorybutton
•ClickontheOKbuttonfromthePropertyManager.TheoptionsrelatedtoModalTimeHistoryAnalysiswillbedisplayed.
ApplyingMaterialandFixture•ClickontheApplyMaterialbuttonfromtheRibbonandselecttheAlloySteelmaterialfromtheMaterialdialogboxdisplayed.
•ClickontheApplybuttonandthenClosebuttonfromtheMaterialdialogbox.
•ClickonthedownarrowbelowFixturesAdvisorbuttonintheRibbonandselect the Fixed Geometry button. The Fixture PropertyManager will be
displayed.
•SelecttheroundbottomfaceoftheboltasshowninFigure-11.
Figure-11.Fixedroundface
•ClickontheOKbuttonfromthePropertyManagertoapplyfixture.
ApplyingHarmonicForce•ClickonthedownarrowbelowExternalLoadsAdvisorbuttonintheRibbon.Listoftoolswillbedisplayed.
•ClickontheForcebuttonfromthelist.TheForce/TorquePropertyManagerwillbedisplayed.
•SelecttheflatfaceoftheboltasshowninFigure-12.
Figure-12.Faceselectedforapplyingforce
•ClickintheForceValueeditboxinthePropertyManagerandspecifythevalueas50N.
•SelecttheCurveradiobuttonfromtheVariationwithTimerolloutinthePropertyManagerandclickontheEditbutton.TheTimeCurvedialogboxwillbedisplayed.
•SelectHarmonicLoadingoptionfromtheShapedrop-downandspecifytheparametersasshowninFigure-13.SpecifytheStarttimeandEndtimeas0and1respectively,inthedialogbox.
Figure-13.ParametersforTimecurve
•ClickontheOKbuttonfromthedialogboxtoapplytheHarmoniccurve.
•ClickontheOKbuttonfromthePropertyManagertoapplytheforce.
RunningtheAnalysisClickontheRunThisStudybuttonfromtheRibbontoseethemagic.StressresultwillbedisplayedasshowninFigure-14.Youalreadyknowtherest
of story about generating other reports like Modal Shape Plot, Frequency
ResponsePlot,andsoon.
Figure-14.Stressreport
In the above analysis, we have seen the effect of vibration on the bolt
during starting of engine. We find that the stress induced is well below
theYieldStrength.But,thejourneyofbolthasnotendedhere.Now,the
bolt has to sustain the continuous harmonic loading due to vibrations of
enginebecauseJimmyisgoingtoNewYorkridinghisbike.
HARMONICANALYSISNow, we have a range of frequency under which the bolt is going to work
duringhiscoursetoNewYork,say0Hzto5000Hz.Notethattheremightbe natural frequencies of bolt in this range which can be dangerous for
Jimmy’ssafety.Let’sseewhetherJimmywillreachNewYorkornot.
StartingHarmonicAnalysis•Openthepartonwhichyouwanttoperformtheanalysis.
•ClickontheSolidWorksSimulationbuttonfromtheSOLIDWORKSAdd-Instab of theRibbon to add Simulation tab in the Ribbon, if not addedalready.
•ClickontheDownarrowbelowtheStudyAdvisorbuttonandselecttheNewStudy tool from the drop-down. List of analysis studies that can be
performed,willbedisplayedintheleft.
•ClickontheLinearDynamicbuttonandthenontheHarmonicbuttonfromtheOptionsrollout;refertoFigure-15.
Figure-15.HarmonicStudybutton
•ClickontheOKbuttonfromthePropertyManager.TheoptionsrelatedtoHarmonicAnalysiswillbedisplayed.
ApplyingMaterialandFixture•ClickontheApplyMaterialbuttonfromtheRibbonandselecttheAlloySteelmaterialfromtheMaterialdialogboxdisplayed.
•ClickontheApplybuttonandthenClosebuttonfromtheMaterialdialogbox.
•ClickonthedownarrowbelowFixturesAdvisorbuttonintheRibbonandselect the Fixed Geometry button. The Fixture PropertyManager will be
displayed.
•SelecttheroundbottomfaceoftheboltasshowninFigure-16.
Figure-16.Fixedroundface
•ClickontheOKbuttonfromthePropertyManagertoapplyfixture.
ApplyingForce•ClickonthedownarrowbelowExternalLoadsAdvisorbuttonintheRibbon.Listoftoolswillbedisplayed.
•ClickontheForcebuttonfromthelist.TheForce/TorquePropertyManagerwillbedisplayed.
•SelecttheflatfaceoftheboltasshowninFigure-17.
Figure-17.Faceselectedforapplyingforce
•ClickintheForceValueeditboxinthePropertyManagerandspecifythevalueas50N.
•ClickinthePhaseAngleeditboxinPhaseAnglerolloutifyouwanttospecifyphaseangle.(Wehavekeptitzero.Remembertheformula;P=A
sin(ωt+φ)whereφisphaseangle).
•ClickontheOKbuttonfromthePropertyManagertoapplytheforce.
SettingFrequencyRange• Right-click on the Harmonic study from theAnalysisManager and selectthe Properties option from the shortcut menu; refer to Figure-18. The
Harmonicdialogboxwillbedisplayed;refertoFigure-19.
Figure-18.Propertiesoption
Figure-19.Harmonicdialogbox
•Specifythenumberoffrequenciestobetestedto10byusingtheNumberoffrequenciesspinnerintheOptionsareaofthedialogbox.
•ClickontheHarmonicoptionstabandspecifytheUpperlimitas5000Hz;refertoFigure-20.
Figure-20.Upperlimitforfrequencies
•ClickontheOKbuttonfromthedialogbox.
Jimmyreachesornot(RunningAnalysis)•ClickontheRunThisStudybuttonfromtheRibbonandwait&watch.TheStressresultwillbedisplayedasshowninFigure-21whichconcludesthat
nobody can stop Jimmy. The stress in bolt is well below the yield
strength.
Figure-21.ResultofHarmonicstudy
There are some situations where you need to see the effect of base
excitationontheobject.Insuchcases,youmightberequiredtoperform
theResponseSpectrumanalysis.Theprocessisgivennext.
RESPONSESPECTRUMANALYSISLet me tell you that Jimmy placed his camera in the side box of his
motorbikebymistakeandthecamerahasexperiencedallthejerksprovided
byroad.Let’sseewhathappenstothebodyofhisnewcamera.Assumethat
theexcitationcausedoncamerabodyis2m/s2.
StartingResponseSpectrumAnalysis•Openthepartonwhichyouwanttoperformtheanalysis(obviouslycamera
body!!).
•ClickonthedownarrowbelowtheStudyAdvisorbuttonandselecttheNewStudy tool from the drop-down. List of analysis studies that can be
performed,willbedisplayedintheleft.
• Click on theLinearDynamic button and then on theResponse SpectrumAnalysisbuttonfromtheOptionsrollout;refertoFigure-22.
Figure-22.ResponseSpectrumAnalysisbutton
•ClickontheOKbuttonfromthePropertyManager.TheoptionsrelatedtoResponseSpectrumAnalysiswillbedisplayed.
ApplyingMaterialandFixture•ClickontheApplyMaterialbuttonfromtheRibbonandselecttheAcrylic(Medium-highimpact)plasticfromtheMaterialdialogboxdisplayed;refertoFigure-23.
Figure-23.Materialdialogboxwithplasticmaterials
•ClickontheApplybuttonandthenClosebuttonfromtheMaterialdialogbox.
•ClickonthedownarrowbelowFixturesAdvisorbuttonintheRibbonandselect the Fixed Geometry button. The Fixture PropertyManager will be
displayed.
•SelectthebottomfaceofthecameraasshowninFigure-24.
Figure-24.Bottomfaceofcamerabodyselected
•ClickontheOKbuttonfromthePropertyManagertoapplyfixture.
ApplyingExcitationNosir!Excitationisnotlinkedwithhumanemotionshere.Excitationisa
displacement, velocity, or acceleration caused in the body due to
vibrations. There are two tools available to define excitation; refer to
Figure-25.
Figure-25.Excitationtools
If you have specified base at more than one faces then you can use the
SelectedBaseExcitationtooltospecifyexcitationforindividualbases.Tospecify the same excitation for all the bases, use the Uniform BaseExcitationtool.
•ClickonthedownarrowbelowExternalLoadsAdvisorbuttonintheRibbon.Listoftoolswillbedisplayed.
•ClickontheUniformBaseExcitationtoolfromthelist.TheUniformBaseExcitationPropertyManagerwillbedisplayed.
•SelecttheAccelerationradiobuttonfromtheTyperolloutandspecify2inverticaldirection;refertoFigure-26.
Figure-26.UniformBaseExcitationPropertyManager
• Click on the OK button from the PropertyManager to apply the
excitation.
Nowwearereadyforthemagic.ClickontheRunThisStudybuttonfromtheRibbonandseewhetherthecameraisinonepieceormorepieces;refertoFigure-27.
Figure-27.ResultofResponseSpectrum
Even if you change the value of Base excitation to 20000 m/s2, still the
camerawillbesafe.Becausethepowerofacrylicplasticwillnotletyou
down.Thisplasticisusedtomakebulletproofshields.
PRACTICE1
In the below problem, you will analyze a driving shaft of automobile for
itsabilitytosustainthetorqueprovidedbyengine.Notethatthedriver
ofthisvehicleisrashdriverandhereallydon’tcareabouthismachine.
So,youmightneedtoperformtherandomvibrationanalysis.Theparameters
for the analysis are given in Figure-28. The model of this problem is
availableinresourcekit.
Figure-28.Parametersforanalysis
SELF-ASSESSMENT
Q1.Staticstudiesassumethatloadsareconstantorappliedataninstant.
(T/F)
Q2.Generallyifthefrequencyofaloadislargerthan1/3ofthelowest
(fundamental)frequencyofobject,adynamicstudyshouldbeused.(T/F)
Q3.Aviscousdamper(ordashpot)generatesaforcethatisproportionalto
mass.(T/F)
Q4.CriticaldampingCcistheleastamountofdampingthatcausesasystem
toreturntoitsequilibriumpositionwithoutoscillating.(T/F)
Q5. If the part has softer elements then Rayleigh Damping can product
unrealisticresultsbecauseofstiffnessmatrixpart.(T/F)
Q6. Which of the following dynamic analysis should be used to find out
stresswhenvariationofeachloadwithtimeisknownexplicitly?
a.ModalTimeHistoryAnalysis
b.HarmonicAnalysis
c.RandomVibrationAnalysis
d.ResponseSpectrumAnalysis
Q7.Whichofthefollowingdynamicanalysisshouldbeusedtocalculatethe
peaksteadystateresponseduetoharmonicloadsorbaseexcitations.
a.ModalTimeHistoryAnalysis
b.HarmonicAnalysis
c.RandomVibrationAnalysis
d.ResponseSpectrumAnalysis
Q8.Whichofthefollowingdynamicanalysisshouldbeusedtocalculatethe
responseduetonon-deterministicloads.
a.ModalTimeHistoryAnalysis
b.HarmonicAnalysis
c.RandomVibrationAnalysis
d.ResponseSpectrumAnalysis
Q9.Inarandomvibrationstudy,loadsaredescribedstatisticallyby…………
functions.
Q10. A displacement, velocity, or acceleration caused in the body due to
vibrationsiscalled…………..
ThermalAnalysis
Chapter9
TopicsCovered
Themajortopicscoveredinthischapterare:
•Introduction
•TypesofThermalAnalysis
•StartingThermalAnalysis.
•ApplyingMaterial.
•DefiningFixtures
•Applyingloads
•DefiningConnections
•SimulatingAnalysis.
•Interpretingresults
INTRODUCTIONThermalanalysisisamethodtocheckthedistributionofheatoverabody
duetoappliedthermalloads.Notethatthermalenergyisdynamicinnature
andisalwaysflowingthroughvariousmediums.Therearethreemechanisms
bywhichthethermalenergyflows:
•Conduction
•Convection
•Radiation
In all three mechanisms, heat energy flows from the medium with higher
temperature to the medium with lower temperature. Heat transfer by
conduction and convection requires the presence of an intervening medium
whileheattransferbyradiationdoesnot.
Theoutputfromathermalanalysiscanbegivenby:
1.Temperaturedistribution.
2.Amountofheatlossorgain.
3.Thermalgradients.
4.Thermalfluxes.
This analysis is used in many engineering industries such as automobile,
piping,electronic,powergeneration,andsoon.
ImportanttermsrelatedtoThermalAnalysisBeforeconductingthermalanalysis,youshouldbefamiliarwiththebasic
conceptsandterminologiesofthermalanalysis.Followingaresomeofthe
importanttermsusedinthermalanalysis:
HeatTransferModesWheneverthereisadifferenceintemperaturebetweentwobodies,theheat
istransferredfromonebodytoanother.Basically,heatistransferredin
threeways:Conduction,
Convection,andRadiation.
Conduction
In conduction, the heat is transferred by interactions of atoms or
moleculesofthematerial.
For example, if you heat up a metal rod at one end, the heat will be
transferredtotheotherendbytheatomsormoleculesofthemetalrod.
ConvectionInconvection,theheatistransferredbytheflowingfluid.Thefluidcan
begasorliquid.Heatingupwaterusinganelectricwaterheaterisagood
exampleofheatconvection.Inthiscase,watertakesheatfromtheheater.
RadiationIn radiation, the heat is transferred in space without any matter.
Radiationistheonlyheattransfermethodthattakesplaceinspace.Heat
comingfromtheSunisagoodexampleofradiation.TheheatfromtheSun
istransferredtotheearththroughradiation.
ThermalGradientThethermalgradientistherateofincreaseintemperatureperunitdepth
inamaterial.
ThermalFluxTheThermalfluxisdefinedastherateofheattransferperunitcross-
sectionalarea.Itisdenotedbyq.
BulkTemperatureIt is the temperature of a fluid flowing outside the material. It is
denotedbyTb.TheBulktemperatureisusedinconvectiveheattransfer.
FilmCoefficientItisameasureoftheheattransferthroughanairfilm.
EmissivityThe emissivity of a material is the ratio of energy radiated by the
material to the energy radiated by a black body at the same temperature.
Emissivity is the measure of a material’s ability to absorb and radiate
heat.Itisdenotedbye.Emissivityisanumericalvaluewithoutanyunit.
Foraperfectblackbody,e=1.Foranyothermaterial,e<1.
Stefan–BoltzmannConstant
Theenergyradiatedbyablackbodyperunitareaperunittimedividedby
thefourthpowerofthebody’stemperatureisknownastheStefan-Boltzmann
constant.Itisdenotedbys.
ThermalConductivityThethermalconductivityisthepropertyofamaterialthatindicatesits
abilitytoconductheat.ItisdenotedbyK.
SpecificHeatThespecificheatistheamountofheatrequiredperunitmasstoraisethe
temperatureofthebodybyonedegreeCelsius.Itisdenotedbyc.
THERMALLOADSTostartthethermalanalysis,clickonthedownarrowbelowStudyAdvisor.Select the New Study button from the tools displayed. The StudyPropertyManagerwillbedisplayed.ClickontheThermal button from theType rollout and click on theOK button from thePropertyManager. Thetools related to thermal analysis will be displayed. Before performing
thermal analysis, we will get familiar with various options required
specifically for thermal analysis. One of the major player in thermal
analysis is the thermal load. To apply the thermal loads, options are
availableintheThermalLoadsdrop-down;refertoFigure-1.Theoptionsinthisdrop-downarediscussednext.
Figure-1.ThermalLoadsdrop-down
TemperatureTheTemperaturetoolisusedtospecifytemperatureofselectedface/faces.Toapplytemperaturefollowthestepsgivennext.
•ClickontheTemperaturetoolfromthelistoftoolsdisplayedonclickdown arrow below Thermal Loads in the Ribbon. The TemperaturePropertyManagerwillbedisplayedasshowninFigure-2.
Figure-2.TemperaturePropertyManager
•Selectthefaceonwhichyouwanttosetthetemperature.
•ClickintheTemperatureeditboxandspecifythedesiredvalue.• If you want to change the unit of temperature from the default Kelvin
unit,thenclickontheKelvin(K)optionnexttoTemperatureeditbox.Thelistofoptionsrelatedtotemperatureunitswillbedisplayed.
•Selectthedesiredunitfromthelist.
• If you are performing the transient thermal study, then the Initialtemperatureradiobuttonwillbeactive;refertoFigure-3.
Figure-3.TemperaturePropertyManagerfortransientstudy
HowtostartTransientThermalAnalysis?Afterstartingthethermalanalysis,right-clickontheanalysisnameintheAnalysisManager;refertoFigure-4.Theoptionsrelatedtoanalysiswillbedisplayedintheshortcutmenu.
SelectthePropertiesoptionfromthemenu.TheThermaldialogboxwillbedisplayed; refer to Figure-5. Select theTransient radio button from theSolutionTypeareaofthedialogbox.Theoptionsrelatedtoanalysistimewill be displayed. Set the desired time duration and increment for the
analysisbyusingtheeditboxes.Theotheroptionsinthisdialogboxhave
alreadybeendiscussedinpreviouschapters.ClickontheOKbuttonfrom
thedialogboxtoapplythesettings.
Figure-4.AnalysisPropertiesshortcutmenu
Figure-5.Thermaldialogbox
•Usingthisoption,youcanspecifythestartingtemperatureoftheface.
Although,itwillchangeautomaticallyundertheapplicationofheatflux.
Youwilllearnmoreaboutthistoollaterwhileperformingtheanalysis.
•IfyouselecttheTemperatureradiobuttonforatransientthermalstudythen the Variation with Time rollout is also displayed in the
PropertyManager;refertoFigure-6.
Figure-6.TemperaturePropertyManagerwithtimevaryingtemperature
•TheoptionsintheVariationwithTimerolloutaresameasdiscussedinpreviouschapters.
•Ifyouwanttoselecttheallexposedfacesofthemodel,thenclickon
theSelectallexposedfacesbuttonfromthePropertyManager.
•Afterspecifyingthedesiredparameters,clickontheOKbuttonfromthe
dialogbox.
ConvectionConvectionisthephenomenabywhichheatistransferredthroughamedium
likeair,fluidorsolid.Everymediumhasitslimitationtotransferthe
heat energy. This limitation is mathematically represented by ConvectionHeatcoefficientQconvection.
Qconvection=hA(Ts-Tf)
Here,hisheattransfercoefficienthasunitW/m2.k
Tsisthetemperatureofthesurface.
Tfisthetemperatureofthesurroundingfluid.
Aistheareaofsurface.
InSolidWorksSimulation,weneedtospecifytheQconvectionfor the convection
phenomena.Thestepstoapplytheheatconvectionaregivennext.
• Click on the down arrow below theThermal Loads from theRibbon. Thelistoftoolswillbedisplayed.
• Select the Convection button from the list of tools. The ConvectionPropertyManagerwillbedisplayedasshowninFigure-7.
Figure-7.ConvectionPropertyManager
•Selectthefacefromwhichtheconvectionisoccurring.
•ClickintheConvectionCoefficienteditboxintheConvectionCoefficientrolloutandspecifythedesiredvalueinit.
• Click in the Bulk Ambient Temperature edit box in the Bulk AmbientTemperature rollout and specify the surrounding temperature for the
analysis.
•Afterspecifyingthedesiredparameters,clickontheOKbuttonfromthe
PropertyManagertoapplytheheatconvection.
HeatPowerThisistheenergyappliedontheselectedfaceintheformofheat.You
can specify the heat power applied on the face by using theHeat Powerbutton.Thestepstousethisbuttonaregivennext.
•ClickonthedownarrowbelowtheThermalLoadsbuttonintheRibbon.Thelistoftoolswillbedisplayed.
• Click on the Heat Power button from the list. The Heat PowerPropertyManagerwillbedisplayed;refertoFigure-8.
•Selectthefaceonwhichyouwanttoapplytheheat.
• Click in the Heat Power edit box in the Heat Power rollout in
PropertyManagerandspecifythedesiredvalueofheatpower.• If you are performing transient thermal study then you can apply a
thermostatconditionbyselectthecheckboxontheThermostat (Transient)rollout.
•OnselectingthecheckboxofThermostat(Transient)rollout,theexpandedrolloutisdisplayed;refertoFigure-9.
Figure-8.HeatPowerPropertyManager
Figure-9.Thermostatrollout
•Clickinthepinkselectionboxintherolloutandselectthevertexthat
youwanttoselectasasensorforthethermostat.
•Inthefirsteditboxbelowthepinkselectionbox,youcanspecifythe
minimumtemperatureforstartinguptheheatpower.
•Inthenexteditbox,youcanspecifythemaximumtemperatureuptowhich
thepowersourcewillprovidetheheat.
•Afterspecifyingthedesiredparameters,clickontheOKbuttonfromthe
PropertyManager.
HeatFluxHeatfluxistheheatenergyappliedperunitareaoftheselectedface.
Thestepstoapplyheatfluxonthemodelaregivennext.
•ClickonthedownarrowbelowThermalLoadsbuttonintheRibbon. Thelistoftoolswillbedisplayed.
• Click on the Heat Flux button from the list. The Heat FluxPropertyManagerwillbedisplayedasshowninFigure-10.
Figure-10.HeatFluxPropertyManager
• The options in this PropertyManager are same as in Heat PowerPropertyManagerandcanbeusedinthesameway.
RadiationThermal radiation is the thermal energy emitted by bodies in the form of
electromagnetic waves because of their temperature. All bodies with
temperatures above the absolute zero emit thermal energy. Because
electromagnetic waves travel in vacuum, no medium is necessary for
radiation to take place. Thermal radiation can occur between ambienttemperaturesurroundingandsurfaceofbodyorbetweensurfaceofonebodyandsurfaceofotherbody.Thestepstospecifyradiationaregivennext.
•ClickondownarrowbelowThermalLoadsbutton.Thelistoftoolswillbedisplayed.
• Click on the Radiation button from the list. The RadiationPropertyManagerwillbedisplayedasshowninFigure-11.
Figure-11.RadiationPropertyManager
•Selectthefacefromwhichtheradiationisoccurring.
• Click in the first edit box in the Radiation Parameters rollout and
specifytheambienttemperatureifyouhaveselectedtheSurfacetoambientradiobuttonfromtheTyperollout.
• If you have selected the Surface to surface radio button from the Typerollout and selected the Open system check box from the RadiationParametersrolloutthenalsoyoucanspecifytheambienttemperatureinthefirsteditboxintheRadiationParametersrollout.
•ClickintheEmissivityeditboxandspecifytheemissioncoefficientforradiation.
•Afterspecifyingthedesiredparameters,clickontheOKbuttonfromthe
PropertyManager.
CONTACTSETWehaveusedconnectionsbetweenvariouspartsofassemblywhileperforming
structural analyses. In the same way, we are also required to specify
connections between various parts of assembly in terms of thermal
properties.Forthermalanalyses,wecanspecifythefollowingconnections:
•ThermalResistance
•Bonded
•Insulated
The tools to specify these connections are available in the ConnectionsAdvisor drop-down. Click on theContact Set tool from the drop-down. TheContactSetsPropertyManagerwillbedisplayedasshowninFigure-12.
Selectthedesiredcontacttypefromthedrop-downintheTyperolloutandselectthefacestoapplythethermalcontacttype.Inthesameway,you
canusetheComponentContactbuttontoapplytheconnectionbetweentwoparts.
ThermalResistanceContactThe thermal resistance contact is used to specify thermal resistance
betweentwocomponentsconnectedinassembly.Onselectingthisoption,the
PropertyManager is displayed as shown in Figure-12. Select the two
contactingfacesofthecomponentsinassemblybyusingtheselectionboxes
inthePropertyManager. Specify the desired value of thermal resistance.TheunitofthermalresistanceisK/W.
BondedContactThe bonded contact is used when there is perfect heat conduction between
twocontactingparts.Notethattheheatflowbetweenpartswilldependon
theirthermalconductance.
Figure-12.ContactSetsPropertyManager
InsulatedContactThe insulated contact is same as No penetration in structural analysis.
This contact is used when there is no heat conduction between the two
contactingparts.
PRACTICALONSTEADYSTATETHERMALANALYSIS
Inthistutorial,wewillperformasteadystatethermalanalysisonareal
worldmodelandcheckthedistributionoftemperature/heatoverthesurface
of the model. Note that model for this practical is available in the
resourcekit.
Startingtheanalysis•Openthepartonwhichyouwanttoperformtheanalysis.
•ClickontheSolidWorksSimulationbuttonfromtheSOLIDWORKSAdd-Instab of theRibbon to add Simulation tab in the Ribbon, if not addedalready.
•ClickontheDownarrowbelowtheStudyAdvisorbuttonandselecttheNewStudy tool from the drop-down. List of analysis studies that can be
performed,willbedisplayedintheleft.
• Click on the Thermal button then click on the OK button from the
PropertyManager.Thetoolsrelatedtothermalanalysiswillbedisplayed.
ApplyingMaterial•ClickontheApplyMaterialbuttonfromtheRibbon.TheMaterial dialogboxwillbedisplayed.
•ExpandtheSolidWorksMaterialsnodeandthentheAluminiumAlloysnodeintheleftofthedialogbox.
• Browse through the materials and select theC355.0-T61 PermanentMoldcast(SS)material;refertoFigure-13.
• Click on theApply button and then click on theClose button from thedialogboxtoexitthedialogbox.
Figure-13.Materialdialogbox
Applyingconvectiontothemodel• Click on the down arrow below Thermal Loads button and select the
Convectionbuttonfromthelist.TheTemperaturePropertyManagerwillbedisplayedasshowninFigure-14.
Figure-14.ConvectionPropertyManager
•SelectalltheinnerfacesofthemodelasshowninFigure-15.
Figure-15.Facesofmodeltobeselected
•Specifytheconvectioncoefficientas10000intheConvectionCoefficient
edit box inPropertyManager. This convection coefficient is for engineoil.
•ClickinBulkAmbientTemperatureeditboxinthePropertyManager andspecifythevalueas400K.
• Click on the OK button from the PropertyManager to apply the
convection.
Applyingheatgeneratedbygascombustionontheheadofthepiston
•ClickonthedownarrowofThermalLoadsintheRibbonandselecttheHeat Power button from the list displayed. The Heat PowerPropertyManagerwillbedisplayed;refertoFigure-16.
Figure-16.HeatPowerPropertyManager
•ClickontheTotalradiobuttonintheSelectedEntitiesrollout.•SelecttheheadfacesofthepistonasshowninFigure-17.
Figure-17.Facestobeselected
•ClickintheHeatPowereditboxintheHeatPowerrollout.Specifythetotalheatpoweras20000.
•ClickontheOKbuttonfromthePropertyManagertoapplytheheat.
RunningtheAnalysis•ClickontheRunbuttonfromtheRibbon.Theanalyzingofproblemwillstart.
• After the analysis is complete. The solution of the analysis will be
displayed;refertoFigure-18.
Figure-18.Solutionofanalysis
•Tochangethetemperaturescale,right-clickontheTemperaturescaleat
theright.Ashortcutmenuwillbedisplayed;refertoFigure-19.
Figure-19.Shortcutmenufortemperaturescale
• Click on the Settings button from the shortcut menu. The Thermal PlotPropertyManagerwillbedisplayed;refertoFigure-20.
•ClickontheDefinitiontabandthenclickontheseconddrop-downintheDisplayrollout;refertoFigure-21.
Figure-20.ThermalPlotPropertyManager
Figure-21.DefinitiontabofThermalPlotPropertyManager
•ClickontheCelsiusoptionfromthelistdisplayedandclickontheOKbuttonfromthePropertyManager.ThescalewillchangetoCelsius.
•YoucanselecttheothercomponentsofThermalanalysisbyright-clicking
ontheTemperaturescaleandselectingthedesiredoptionfromtheThermalComponentcascadingmenu;refertoFigure-22.
Figure-22.ThermalComponents
SWITCHINGFROMSTEADYSTATEANALYSISTOTRANSIENTTHERMALANALYSIS
Earlier,wehaveperformedthesteadystateanalysis.Now,wewillusethe
aboveanalysisandswitchtotransientthermalanalysis.Theprocedureto
switchtotransientthermalanalysisisgivennext.
• Right-click on the name of analysis in theAnalysisManager; refer toFigure-23.
• Click on the Properties button from the menu displayed. The Thermaldialogboxwillbedisplayed;refertoFigure-24.
Figure-23.Shortcutmenuforanalysisproperties
Figure-24.Thermaldialogbox
•ClickontheTransientradiobutton.Theeditboxesbelowitwillbecomeactive.
•Specifythetotaltimeofstudy(inseconds)intheTotaltimeeditboxas10seconds.
•ClickintheTimeincrementeditboxandspecifytheincrementvalueinsecondsas1.
•Ifyouhaveearlierperformedanyotheranalysisfromwhereyouwantto
import the temperature as the initial value then click on the Initialtemperature from thermal study check box and then select the study namefromthedrop-down.
•Youcanalsoselectthedesiredstepnumberfromtheadjacentspinner.
•SelectthedesiredsolverfromtheSolverareaofthedialogboxandthenclickontheOKbuttonfromthedialogbox.
SpecifyingInitialTemperatureNow,weneedtospecifytheinitialtemperaturefortheanalysisifwehave
notimporteditfromanyearlierstudy.
• Click on theTemperature button from theThermalLoads drop-down. TheTemperaturePropertyManagerwillbedisplayed.
• Select the Initial Temperature radio button and select all the faces byusingSelectallexposedfacesbuttonasshowninFigure-25.
Figure-25.Facestobeselectedforinitialtemperature
• Click in theTemperature edit box and in theTemperature rollout andspecifythevalueas25°C.
• Click on the OK button from the PropertyManager to apply the
temperature.
Runningtheanalysis•ClickontheRunbuttontoruntheanalysis.• After the analysis is complete, compare the two results. You will find
thattheanalysistemperaturerangeischangingandthepartisdisplayed
cooler than earlier one. This is because we have allowed the time for
cooling in analysis and we have specified the initial temperature as
25°C.•Whenyouanimatetheresult,wewillfindthatheatistransferredfrom
topfacetosidewallsasthetimepasses.
UsingProbetofindouttemperature•Afterrunningtheanalysis,right-clickinthemodelingarea.Ashortcut
menuwillbedisplayed.
•SelecttheProbebuttonfromtheshortcutmenu;refertoFigure-26.
Figure-26.Probebutton
•TheProbeResultPropertyManagerwillbedisplayed;refertoFigure-27.Figure-27.ProbeResultPropertyManager
• Click on the model at the desired position. The temperature and other
parametersoftheselectedpositionwillbedisplayedinaboxandResultsrolloutofPropertyManager;refertoFigure-28.
Figure-28.Temperatureoutput
• Click on the Plot button from the Report Options rollout of the
PropertyManagertocheckthegraphoftemperaturechange.
Note that to be able to perform the analysis using the SolidWorks
Simulationsoftware,youshouldbeabletoanswerthefollowingquestions:
1.Heattransferthroughasolidbodyisreferredtoas
oConductionoConvectionoRadiationoGeneration
2.Thetemperaturegradientisdefinedas
oTemperaturerateofchangeperunitlength
oHeatflowthroughabody
oTemperaturerateofchangeperunitvolume
oTemperaturerateofchangeperunitarea
3.Heatfluxisdefinedby
oTheamountofheatgeneratedperunitvolume
oTheheattransferrateperunitarea
oTheamountofheatstoredinacontrolvolume
oThetemperaturechangeperunitlength
4.Heattransferbetweenasolidbodyandafluidisreferredtoas
oConductionoConvectionoRadiationoGeneration
5.Which behavior best describes a material with a high thermal conductivitycomparedtoamaterialwillasmallerthermalconductivity?
oTemperaturechangeissmallerthroughthesolid
oHeatfluxishigherthroughthesolid
oThermalresistanceislowerthroughthesolid
oAlloftheabove
6.Theconvectioncoefficientisrelatedto
oTheratethatheatistransferredbetweenasolidandfluid
oTheratethatheatistransferredbetweentwosolids
oTheemissivepowerofthematerial
oTheheatgenerationcapabilityofthematerial
7.Theamountofheattransferredbyradiationisdirectlyrelatedto
oTheStephan-Boltzmannconstant
oThesurfacetemperature
oTheemissivityofthematerial
oAlloftheabove
8.Ifnoheatistransferredtoorfromasurface,itisreferredtoas
oIsothermaloExothermaloAdiabaticoIsobaric
9.Whenalltemperaturesareinequilibrium,theproblemisassumedtobe
oTransient
oSteady-State
oLaminar
oNoneoftheabove
10.Whichofthefollowingtermsisnotpartoftheenergybalanceforheattransfer?
oGeneratedenergy
oStoredenergy
oEnergyintothesystem
oEnergydestroyed
*********************************************************
PROBLEM1
Ametalsphereofdiameterd=35mmisinitiallyattemperatureTi=700K.
Att=0,thesphereisplacedinafluidenvironmentthathaspropertiesof
T∞=300Kandh=50W/m2-K.Thepropertiesofthesteelarek=35W/m-K,
ρ = 7500 kg/m3, and c = 550 J/kg-K. Find the surface temperature of the
sphereafter500seconds.
PROBLEM2
Aflangedpipeassembly;refertoFigure-29,madeofplaincarbonsteelis
subjected to both convective and conductive boundary conditions. Fluid
inside the pipe is at a temperature of 130°C and has a convection
coefficientofhi=160W/m2-K.Airontheoutsideofthepipeisat20°C
andhasaconvectioncoefficientofho=70W/m2-K.Therightandleftends
ofthepipeareattemperaturesof450°Cand80°C,respectively.Thereisa
thermal resistance between the two flanges of 0.002 K-m2/W. Use thermal
analysis to analyze the pipe under both steady state and transient
conditions.
Figure-29.Flangedpipeassembly
BucklingAnalysis
Chapter10
TopicsCovered
Themajortopicscoveredinthischapterare:
•Introduction
•StartingBucklingAnalysis.
•ApplyingMaterial.
•DefiningFixtures
•Applyingloads
•DefiningConnections
•SimulatingAnalysis.
•Interpretingresults
INTRODUCTIONSlendermodelstendtobuckleunderaxialloading.Bucklingisdefinedas
thesuddendeformationwhichoccurswhenthestoredmembrane(axial)energy
isconvertedintobendingenergywithnochangeintheexternallyapplied
loads. Mathematically, when buckling occurs, the stiffness becomes
singular.TheLinearizedbucklingapproach,usedhere,solvesaneigenvalue
problem to estimate the critical buckling factors and the associated
bucklingmodeshapes.
Amodelcanbuckleindifferentshapesunderdifferentlevelsofloading.
Theshapethemodeltakeswhilebucklingiscalledthebucklingmodeshape
andtheloadingiscalledthecriticalorbucklingload.Bucklinganalysis
calculatesanumberofmodesasrequestedintheBucklingdialog.Designers
areusuallyinterestedinthelowestmode(mode1)becauseitisassociated
withthelowestcriticalload.Whenbucklingisthecriticaldesignfactor,
calculatingmultiplebucklingmodeshelpsinlocatingtheweakareasofthe
model.Themodeshapescanhelpyoumodifythemodelorthesupportsystem
topreventbucklinginacertainmode.
A more vigorous approach to study the behavior of models at and beyond
bucklingrequirestheuseofnonlineardesignanalysiscodes.
Inalaymen’slanguage,ifyoupressdownonanemptysoftdrinkcanwith
yourhand,notmuchwillseemtohappen.Ifyouputthecanonthefloor
andgraduallyincreasetheforcebysteppingdownonitwithyourfoot,at
some point it will suddenly squash. This sudden scrunching is known as
“buckling.”
Modelswiththinpartstendtobuckleunderaxialloading.Bucklingcanbe
defined as the sudden deformation, which occurs when the stored membrane
(axial) energy is converted into bending energy with no change in the
externally applied loads. Mathematically, when buckling occurs, the total
stiffnessmatrixbecomessingular.
In the normal use of most products, buckling can be catastrophic if it
occurs.Thefailureisnotonebecauseofstressbutgeometricstability.
Oncethegeometryofthepartstartstodeform,itcannolongersupport
even a fraction of the force initially applied. The worst part about
buckling for engineers is that buckling usually occurs at relatively low
stressvaluesforwhatthematerialcanwithstand.Sotheyhavetomakea
separatechecktoseeifaproductorpartthereofisokaywithrespectto
buckling.
Slender structures and structures with slender parts loaded in the axial
direction buckle under relatively small axial loads. Such structures may
fail in buckling while their stresses are far below critical levels. For
suchstructures,thebucklingloadbecomesacriticaldesignfactor.Stocky
structures, on the other hand, require large loads to buckle, therefore
bucklinganalysisisusuallynotrequired.
Bucklingalmostalwaysinvolvescompression.Incivilengineering,buckling
is to be avoided when designing support columns, load bearing walls and
sectionsofbridgeswhichmayflexunderload.ForexampleanI-beammaybe
perfectly
“safe”whenconsideringonlythemaximumstress,butfaildisastrouslyif
justonelocalspotofaflangeshouldbuckle!Inmechanicalengineering,
designs involving thin parts in flexible structures like airplanes and
automobiles are susceptible to buckling. Even though stress can be very
low,bucklingoflocalareascancausethewholestructuretocollapsebya
rapidseriesof‘propagatingbuckling’.
Buckling analysis calculates the smallest (critical) loading required for
buckling a model. Buckling loads are associated with buckling modes.
Designers are usually interested in the lowest mode because it is
associated with the lowest critical load. When buckling is the critical
design factor, calculating multiple buckling modes helps in locating the
weakareasofthemodel.Thismaypreventtheoccurrenceoflowerbuckling
modesbysimplemodifications.
USEOFBUCKLINGANALYSISSlenderpartsandassemblieswithslendercomponentsthatareloadedinthe
axialdirectionbuckleunderrelativelysmallaxialloads.Suchstructures
canfailduetobucklingwhilethestressesarefarbelowcriticallevels.
For such structures, the buckling load becomes a critical design factor.
Bucklinganalysisisusuallynotrequiredforbulkystructuresasfailure
occursearlierduetohighstresses.Theproceduretousebucklinganalysis
inSolidWorksSimulationisgivennext.
StartingtheBucklingAnalysis•Openthepartonwhichyouwanttoperformtheanalysis.
•ClickontheSolidWorksSimulationbuttonfromtheSOLIDWORKSAdd-Instab of theRibbon to add Simulation tab in the Ribbon, if not addedalready.
•ClickontheDownarrowbelowtheStudyAdvisorbuttonandselecttheNewStudy tool from the drop-down. List of analysis studies that can be
performed,willbedisplayedintheleft.
•ClickontheBucklingbutton.ThetoolsrelatedtobucklinganalysiswillbedisplayedintheRibbon.
SettingtheNumberofBucklingModes•ClickontheStudyPropertiestoolfromtheStudyAdvisordrop-downintheRibbon.TheBucklingdialogboxwillbedisplayedasshowninFigure-1.
• Specify the desired number of buckling modes in theNumber of bucklingmodesspinnerinthedialogbox.
•ClickontheOKbuttonfromthedialogboxtoapplythechanges.
Figure-1.Bucklingdialogbox
ApplyingMaterial•ClickontheApplyMaterialbuttonfromtheRibbon.TheMaterial dialogboxwillbedisplayed;refertoFigure-2.
•Selectthe1060AlloymaterialunderAluminiumAlloysnode.
• Click on the Apply button and then select the Close button from the
dialogbox.
ApplyingFixture•ClickonthedownarrowbelowFixturesAdvisorintheRibbon.Thelistoftoolswillbedisplayed.
• Click on the Fixed Geometry button from the list. The FixturePropertyManagerwillbedisplayed;refertoFigure-3.
Figure-2.Materialdialogbox
Figure-3.FixturePropertyManager
•SelectthefaceasshowninFigure-4.
Figure-4.Faceforfixture
•ClickontheOKbuttonfromthePropertyManagertoapplythefixture.
ApplyingtheForce• Click on the down arrow belowExternal Loads Advisor in theRibbon. Alistoftoolswillbedisplayed.
•ClickontheForcebuttonfromthelist.TheForce/TorquePropertyManagerwillbedisplayed;refertoFigure-5.
Figure-5.ForceTorquePropertyManager
•SelectthefaceasshowninFigure-6.
•ClickintheForceValueeditboxinthePropertyManagerandspecifythevalueofforceas1000.
Figure-6.Faceforapplyingforce
•ClickontheOKbuttonfromthePropertyManagertoapplytheforces.
RunningtheAnalysis• Click on the Run button from the Ribbon. The analysis will start
solving.
• After the analyzing is complete, the result will be displayed in the
modelingarea;refertoFigure-7.
Figure-7.Result
•Fromtheabovefigure,youcancheckthattheloadfactorforthismodel
is2.7792.Thisloadfactorrepresentsthefactorofsafetyforthemodel.•Accordingtotheabovevalue,themodelisabletosustaintheloadfor
buckling.
• Note that although the part will not fail under the given load but it
willbedeformedasperthescalesoyoushouldalsocheckthenon-linear
staticanalysisresults.
MeaningofdifferentvaluesofloadfactoraregiveninFigure-8.
Figure-8.Bucklingloadfactor
SELF-ASSESSMENT
Q1. Once the geometry of the part starts to deform, it can no longer
supportevenafractionoftheforceinitiallyapplied.(T/F)
Q2.Bucklingoccursatrelativelylowstressvaluesforwhatthematerial
canwithstand.(T/F)
Q3. Buckling analysis is usually not required for bulky structures as
failureoccursearlierduetohighstresses.(T/F)
Q4.TheloadfactorinBucklinganalysisresultsrepresentsthefactorof
safetyforthemodel.(T/F)
Q5.Iftheloadfactoris1thenourmodelissafefrombuckling.(T/F)
FatigueAnalysis
Chapter11
TopicsCovered
Themajortopicscoveredinthischapterare:
•Introduction
•StartingFatigueAnalysis.
•Selectingthepreviousanalysis
•Definingthenumberofcycles
•SimulatingAnalysis.
•Interpretingresults
INTRODUCTIONRepeated loading and unloading weakens objects over time even when the
induced stresses are considerably less than the allowable stress limits.
This phenomenon is known as fatigue. Each cycle of stress fluctuation
weakens the object to some extent. After a number of cycles, the object
becomessoweakthatitfails.Fatigueistheprimecauseofthefailureof
manyobjects,especiallythosemadeofmetals.Examplesoffailuredueto
fatigue include, rotating machinery, bolts, airplane wings, consumer
products,offshoreplatforms,ships,vehicleaxles,bridges,andbones.
Linear and nonlinear structural studies do not predict failure due to
fatigue.Theycalculatetheresponseofadesignsubjectedtoaspecified
environment of restraints and loads. If the analysis assumptions are
observedandthecalculatedstressesarewithintheallowablelimits,they
concludethatthedesignissafeinthisenvironmentregardlessofhowmany
timestheloadisapplied.
Resultsofstatic,nonlinear,ortimehistorylineardynamicstudiescanbe
used as the basis for defining a fatigue study. The number of cycles
requiredforfatiguefailuretooccuratalocationdependsonthematerial
andthestressfluctuations.Thisinformation,foracertainmaterial,is
providedbyacurvecalledtheSNcurve.
StagesofFailureDuetoFatigueFailureduetofatigueoccursinthreestages:
Stage 1 One or more cracks develop in the material. Cracks can develop
anywhere in the material but usually occur on the boundary faces due to
higher stress fluctuations. Cracks can occur due to many reasons.
Imperfections in the microscopic structure of the materials and surface
scratchescausedbytoolingorhandlingaresomeofthem.
Stage2Someorallthecracksgrowasaresultofcontinuedloading.
Stage3Theabilityofthedesigntowithstandtheappliedloadscontinuetodeteriorateuntilfailureoccurs.
Fatigue cracks start on the surface of a material. Strengthening the
surfacesofthemodelincreasesthelifeofthemodelunderfatigueevents.
From the above theory, you can find out that the main player in Fatigue
analysisisthepropertiesofmaterialsrathertheS-Ncurves.
TheproceduretoperformtheFatigueanalysisisgivennext.
StartingFatigueAnalysis• Open a part on which you have already performed Static or dynamic
analysis.(WehaveopenedthefileusedinChapter3ofthisbook;refer
toFigure-1.)
Figure-1.Modelofchapter3
Figure-2.Variableamplitudehistorydatabutton
•ClickonthedownarrowbelowStudyAdvisor,thelistoftoolswillbedisplayed.
•ClickontheNewStudybuttonfromthelist.TheStudyPropertyManagerwillbedisplayed.
•ClickontheFatiguebuttonfromthelistandthenclickontheVariableamplitude history data button from the Options rollout of the
PropertyManager;refertoFigure-2.
Note that in this example, we will study the Variable amplitude history
datafatiguestudybutinSolidWorkssimulation,wecanperformfourtype
offatigueanalysesviz.Constantamplitudeeventswithdefinedcycles,Variableamplitude history data, Harmonic- fatigue of sinusoidal loading, and Randomvibration-fatigue of random vibration. The procedure of all the studies is
almostthesame.
In case of Constant amplitude events with defined cycles, the load being
applied on the object is constant and we specify the number of loading
cyclestotestthefatigue.
IncaseofVariableamplitudehistorydata,theloadappliedonobjectvaries
withtime.Thisvariationcanbedefinedinthefatiguestudyitself.
IncaseofHarmonic-fatigueofsinusoidalloading,thedynamicloadisappliedintheformofsinusoidalcurve.Forthistypeoffatiguestudy,werequire
thedatafromstudiesperformedunderLinearDynamiccategory.
IncaseofRandomvibration-fatigueofrandomvibration,werequirethedatafromrandomvibrationstudy.Toperformthisstudy,youneedtoperformthe
randomvibrationstudyfirst.
• Note that if you want to study for a constant amplitude then you can
select the Constant amplitude events with defined cycles button from the
Optionsrollout.
•ClickontheOKbuttonfromthePropertyManagertostarttheanalysis.Thetoolsrelatedtofatigueanalysiswillbedisplayed;refertoFigure-
3.
Figure-3.Toolsforfatigueanalysis
InitiatingFatigueAnalysis•ClickonthedownarrowbelowFatigueintheRibbon.TheAddEventtoolwillbedisplayed.
• Click on theAdd Event tool. TheAdd Event (Variable) PropertyManagerwillbedisplayed;refertoFigure-4.
Figure-4.AddEventPropertyManager
•Bydefault,Static1studyisaddedintheeventlist.
•ClickintheNumberofrepeatsspinnerintheOptionsrolloutandspecifythe number of repetitions as300 for the load curve being generated inthenextsegment.
Now,weneedtospecifythetimecurveforthefatigueanalysis.
•ClickontheGetCurvebuttonfromthePropertyManager.TheLoadHistoryCurvedialogboxwillbedisplayed;refertoFigure-5.
Figure-5.LoadHistoryCurvedialogbox
•ClickintheNamefieldandspecifythedesirednameofthecurve.
•ClickontheTypedrop-downandselecttheTime&litudeoptionfromthelistdisplayed.
•ThetableoftimeversusamplitudeisdisplayedintheCurvedataarea.
•Double-clickonthe1buttonunderthePointcolumn.Thenextpointwillbeaddedinthetable;refertoFigure-6.
Figure-6.Curvedataafteraddingonemorepoint
•Similarly,youcanaddmorepoints.
•Enterthedatarelatedtoamplitudeinthetable;refertoFigure-7.
Figure-7.Curvedatatablewithcustomvalues
•ClickontheOKbuttonfromthedialogbox.
•ClickontheOKbuttonfromthePropertyManagertoaddtheevent.
ApplyingorEditingS-Ndata•Right-clickonthenameofthemodelintheAnalysisManagerandselecttheApply/EditFatiguedatabutton;refertoFigure-8.
Figure-8.ApplyEditFatigueDatabutton
•TheFatigueSNCurvestabinMaterialsdialogboxwillbedisplayed;refertoFigure-9.
Figure-9.FatigueSNCurvetabinMaterialsdialogbox
•Ifyouhavethetableofparametersthenspecifythedataasdoneincase
ofCurve Data. In this case, we will use the fatigue data of ASMEAusteniticSteel.
• Click on theDerive from material Elastic Modulus radio button from theSourceareainthedialogbox.Thedatawillbeimportedautomaticallyinthetable.
•ClickontheApplybuttonandthenClosebuttonfromthedialogbox.
ModifyingtheStaticAnalysisearlierperformed• Click on the Static 1 tab in the bottom bar of SolidWorks; refer to
Figure-10.Thestaticanalysiswillopen;refertoFigure-11.
Figure-10.Static1tab
Figure-11.Staticanalysisearlierperformed
•DoubleclickontheForce-1nodeintheAnalysisManager;refertoFigure-11.TheForce/TorquePropertyManagerwillbedisplayed.
•ChangetheforcevalueinthePropertyManagerto1800andclickontheOKbuttonfromthePropertyManager.
• Click on the Run This Study button from the Ribbon to update the
analysis.
RunningtheFatigueAnalysis• Click on theFatigue 1 tab from the bottom bar of SolidWorks. You willswitchbacktofatigueanalysis.
•ClickontheRunThisStudybuttonfromtheRibbon.
• Double-click on the Results2 (-Life-) node in the Analysis Manager. The
resultswillbedisplayedasshowninFigure-12.
Figure-12.Results
•Fromtheresults,wecanfindoutthatthepartwillfailon506thcycleatthelocationpaintedinred.
•Theredlocationisbelowthegreenmarkedarea,soyouneedtorotate
themodel;refertoFigure-13.
Figure-13.Locationinred
ChangingPropertiesofFatigueAnalysis•Right-clickontheFatigue1(-Default-)nodeintheAnalysisManager.Theoptionsrelatedtofatigueanalysiswillbedisplayed.
•ClickonthePropertiesbuttonfromthelistdisplayed.TheFatiguedialogboxwillbedisplayed;refertoFigure-14.
Figure-14.Fatiguedialogbox
•TheNo.ofBinsforrainflowcountingspinnerisusedtospecifythenumberofdivisionsofloadfrequencyforspecifiedamplitude.
• The options in the Computing alternating stress using area are used to
specifytheanalysisresulttobeusedfortestingfatigue.
• The options in the Mean stress correction area are used to set the
correctiononthebasisofmaterialproperties.Describedas:
None:Nocorrection.
Goodmanmethod:Generallysuitableforbrittlematerials.
Gerbermethod:Generallysuitableforductilematerials.
Soderbergmethod:Generallythemostconservative.
•Whenmeshingisdone,SolidWorkscreatestwotypeofshellelements:Top
faceshellelementsandBottomfaceshellelements.Thiselementscanbe
distinguishedbytheircolor.TheShellfaceareaofthedialogboxallows
you to select the faces that you want to use for performing fatigue
analysis.
• TheFatigue strength reduction factor (Kf) edit box is used to specify thevalue of fatigue reduction factor for allowing environment factor in
analysis.Usethisfactor,between0and1,toaccountfordifferencesin
test environment used to generate the S-N curve and the actual loading
environment. The program divides the alternating stress by this factor
beforereadingthecorrespondingnumberofcyclesfromtheS-Ncurve.This
is equivalent to reducing the number of cycles that cause failure at a
certainalternatingstress.Fatiguehandbookssuggestnumericvaluesfor
thefatiguestrengthreductionfactor.
• The Filter load cycles below edit box forces the system to filter out
load cycles with ranges smaller than the specified percentage of the
maximumrange.Forexample,ifyouspecify5%,theprogramignorescycles
withloadrangeslessthan5%ofthemaximumrangeoftheloadhistory.
Usethisparametertofilteroutnoisefrommeasuringdevices.
RUNNINGCONSTANTAMPLITUDEEVENTSONTHEMODEL
•StartanewstudyofFatiguebyusingtheConstantamplitudebuttonfromtheStudyPropertyManager;refertoFigure-15.ClickontheOKbuttontostarttheanalysis.
Figure-15.Constantamplitudebutton
•ClickontheAddEventbuttonfromtheFatiguedrop-downintheRibbon.The Add Event(Constant) PropertyManager will be displayed as shown in
Figure-16.
Figure-16.AddEventConstantPropertyManager
•Makesurethenumberofcyclesare1000intheCycleseditbox.ClickontheOKbuttonfromPropertyManager.
• Click on the Run This Study button from the Ribbon. The results of
constantloadingwillbedisplayedasshowninFigure-17.
Figure-17.Resultofconstantloadingfatigue
SELF-ASSESSMENT
Q1.Linearandnonlinearstructuralstudiesdonotpredictfailuredueto
fatigue.(T/F)
Q2. Results of static, nonlinear, or time history linear dynamic studies
canbeusedasthebasisfordefiningafatiguestudy.(T/F)
Q3. The number of cycles required for fatigue failure to occur at a
locationdependsonthematerialnotonthestressfluctuations.(T/F)
Q4.Cracksduetofatiguecandevelopanywhereinthematerialbutusually
occurontheboundaryfacesduetohigherstressfluctuations.(T/F)
Q5.Strengtheningthesurfacesofthemodeldoesnotaffectthelifeofthe
modelunderfatigueevents.(T/F)
Drop-Test
Chapter12
TopicsCovered
Themajortopicscoveredinthischapterare:
•Introduction
•StartingDrop-Test
•ApplyingMaterial
•Settingdropparameters
•SimulatingAnalysis.
•Interpretingresults
INTRODUCTIONInadroptestanalysis,thetimevaryingstressesanddeformationsdueto
an initial impact of the product with a rigid or flexible planar surface
(thefloor)arecalculated.Astheproductdeforms,secondaryinternaland
external impacts are also calculated, locating critical weaknesses or
failurepoints,aswellasstressesanddisplacements.Droptestanalysis
using SolidWorks Simulation enables you to visualize the elastic stress
wave propagating through the system so that the correct assembly methods
areused.
The maximum “g force” experienced by individual components is one of the
primary unknowns before a drop test. This is a critical parameter since
many electronic and mechanical components are not rated for further use
aboveaspecifiedmaximumgforce.UsingdroptestanalysiswithSolidWorks
Simulation, designers and engineers can measure the time varying
accelerations (g force) at any location within the product, providing
critical design information and reducing the number of physical tests
needed.Adesignteamcaneasilyverifyperformancewhiletheydesignand
select the correct materials, component shape, and fixture methods to
ensurethatcriticalcomponentsstaywithintheir“maxgforce”limits.
STARTINGDROPTEST•Openthepartonwhichyouwanttoperformthedrop-test.
•ClickontheSolidWorksSimulationbuttonfromtheSOLIDWORKSAdd-Instab of theRibbon to add Simulation tab in the Ribbon, if not addedalready.
•ClickontheDownarrowbelowtheStudyAdvisorbuttonandselecttheNewStudytoolfromthedrop-down.ListofanalysisstudieswillbedisplayedintheStudyPropertyManager.
•ClickontheDropTestbuttonfromthelistandclickontheOKbutton
from the PropertyManager. The tools related to drop-test will be
displayed;refertoFigure-1.
ApplyingMaterial•Right-clickonnameofthemodeli.e.ScaleBase.Ashortcutmenuwillbe
displayed.
•ClickonApply/EditMaterialbuttonfromtheshortcutmenu.TheMaterialdialogboxwillbedisplayed.
•SelecttheABSPCMaterialfromthePlasticcategoryintheleft;refertoFigure-2.
Figure-1.Toolsrelatedtodroptest
Figure-2.Materialdialogboxwithmaterialtobeselected
• Click on theApply button and then click on theOK button from the
dialogbox.
If you are working on an assembly then you can apply the contacts as
discussedinearlierchapters.
CreatingMesh•Right-clickontheMeshintheAnalysisManager.Ashortcutmenuwillbedisplayed.
•ClickontheSimplifyModelforMeshingbuttonfromtheshortcutmenu.TheSimplifytaskpanewillbedisplayed;refertoFigure-3.
Figure-3.Simplifytaskpane
•ClickontheFindNowbuttontofindtheareasthatcreatecomplexityinmeshing.ThecomplexareasaredisplayedbelowResultsintheSimplifytaskpane;refertoFigure-4.
Figure-4.Resultsintaskpane
•ClosetheSimplifytaskpaneandselectalltheelementsbyholdingCTRLkeywhileselectingfromtheFeatureManager.
• Right-click on any of the selected element and select the Suppressbutton;refertoFigure-5.
Figure-5.Suppressbutton
•Ondoingso,theselectedelementswillbesuppressed.
•Again,right-clickonMeshintheAnalysisManagerandselecttheCreateMesh button. The Mesh PropertyManager will be displayed; refer to
Figure-6.
Figure-6.MeshPropertyManager
• Set the mesh density as per your system capabilities and accuracy
requirement.
•ClickontheOKbuttonfromthePropertyManagertocreatethemesh.
ParametersforDrop
•Right-clickontheSetupnodefromtheAnalysisManager.Ashortcutmenuwillbedisplayed;refertoFigure-7.
• Click on the Define/Edit button from the menu. The Drop Test SetupPropertyManagerwillbedisplayed;refertoFigure-8.
Figure-7.Setupshortcutmenu
Figure-8.DropTestSetupPropertyManager
•Ifyouknowthevelocityoftheobjectbeingdroppedthenclickonthe
Velocity at impact radio button from the Specify rollout in the
PropertyManager.TheVelocityat Impactrolloutwillbedisplayedinthe
PropertyManager;refertoFigure-9.
Figure-9.VelocityatImpactrollout
•SelectthereferenceforvelocitydirectionandselecttheReversebuttonadjacenttotheselectionboxintherollout.
•EnterthedesiredvelocityintheeditboxinVelocityatImpactrollout.
• If you know height of the object from where it is being dropped, then
click on the Drop height radio button. The Height rollout will be
displayed;refertoFigure-10.NotethattheDropheightradiobuttonisselectedbydefault.
Figure-10.Heightrollout
• Select the From centroid radio button if you want to specify the dropheight from centroid of the model or select the From lowest point radiobutton if you want to specify the height from the lowest point of the
model.
•SpecifythedropheightintheeditboxinHeightrollout.
• Click in the Pink selection box in theGravity rollout and select theplane/face/edgeforspecifyingthegravitydirectionreference.
•Selectthefacefordirectionreference;refertoFigure-11.
Figure-11.Faceselectedforgravityreference
•Youcanchangethegravitationalaccelerationasperyourrequirementby
usingtheGravityMagnitudeeditboxintheGravityrollout,ifrequired.
• Select theNormal to gravity radio button in theTarget rollout if thetargetplane(ground)isnormaltogravitydirection.
•SelecttheParalleltoref.planeradiobuttonandselectthereferenceplaneforspecifyingthegroundorientationasperyourrequirement.
•Youcanspecifythefrictioncoefficientforselectedmaterialbyusing
theFrictionCoefficienteditbox,ifrequired.
•IftheflooristoughthenselecttheRigidtargetradiobutton.IfyourfloorissoftthenselecttheFlexibletargetradiobuttonandspecifytherelatedparametersintheStiffnessandThicknessrolloutdisplayedinthePropertyManager.
•TheeditboxinContactDampingrolloutisusedtospecifythedampingratioforcollision.
•Afterspecifyingthedesiredparameters,clickontheOKbuttonfromthe
PropertyManagertoapplythesettings.
RunningtheAnalysis•ClickontheRunbuttonfromtheRibbon.Systemwillstartsolvingtheanalysis.
• After the analysis is solved, the results will be displayed; refer to
Figure-12.
Figure-12.Results
• You can create more plots by right-clicking on Results node in the
AnalysisManagerandselectingthedesiredresultoption.
PressureVesselDesign&DesignStudy
Chapter13
TopicsCovered
Themajortopicscoveredinthischapterare:
•StartingPressureVesselDesign.
•InclusionofAnalyses
•SimulatingDesignStudy
•StartingDesignStudy
•SpecifyingVariables
•SettingConstraints
•SettingGoals
•Evaluatingresults
INTRODUCTIONPressure vessels are containers that store the pressurized fluids. A
pressure vessel can be of any practical shape but generally spherical,
cylindrical, and conical shapes are employed. The most important question
for pressure vessel designer is whether the designed vessel will sustain
therequired conditions or not. SolidWorks Simulation provides a separate
optiontoperformthisstudynamedPressureVesselDesignstudy.
InaPressureVesselDesignstudy,youcombinetheresultsofstaticstudieswith the desired factors. Each static study has a different set of loads
that produce corresponding results. These loads can be dead loads, live
loads(approximatedbystaticloads),thermalloads,seismicloads,andso
on. The Pressure Vessel Design study combines the results of the static
studiesalgebraicallyusingalinearcombinationorthesquarerootofthe
sumofthesquares(SRSS).
BeforewestartperformingthePressureVesselDesignstudy,theremustbe
two or more static analyses performed on the vessel earlier. In the next
example, we have already performed two static analyses and one thermal
analysisonthemodel.Detailsoftheseanalysesaregivenasfollows:
ThermalAnalysis1ParametersforthermalanalysisaregiveninFigure-1.
Figure-1.Parametersforthermalanalysis
You can perform the analysis as per the above figure for your practice.
Note that the analysis is already performed in the part file supplied in
theResourcekit.
StaticAnalysis1&2IntheFigure-2,theparametersforstaticanalysis1aregivenandinthe
Figure-3parametersforstaticanalysis2aregiven.
Figure-2.Parametersforstaticanalysis1
Figure-3.Parametersforstaticanalysis2
STARTINGPRESSUREVESSELDESIGNSTUDY•Openthefileonwhichyouhaveperformedtheabovegivenanalyses.
• Click on theSimulation tab in theRibbon and click on the down arrowbelowStudyAdvisor.Listoftoolswillbedisplayed.
•ClickontheNewStudybuttonandselectthePressureVesselDesignbuttonfromthePropertyManager.
•ClickontheOKbuttonfromthePropertyManagertodisplaythetoolsrelatedtoPressureVesselDesignStudy;refertoFigure-4.
Figure-4.Toolsforpressurevesseldesign
SetupforDesignStudy•RightclickontheSetupnodeintheAnalysisManager.Ashortcutmenuwillbedisplayed;refertoFigure-5.
• Click on the Define/edit button. The Result Combination SetupPropertyManagerwillbedisplayed;refertoFigure-6.
Figure-5.Shortcutmenuforsetup
Figure-6.ResultCombinationSetupPropertyManager
There are two ways to combine various analyses results to study pressure
vessel design; Linear combination and SRSS. Select theLinear combinationradio button to linearly add the results of various studies to display
finalresult.IfyouselecttheSRSSradiobuttonthenthesquarerootofthesumofthesquaresstudyresultswillbeusedtorepresentthefinal
result.
• Click in the field belowStudy column, the field will be converted todrop-down.
•Clickonthedownarrowofdrop-down.Thelistofstaticanalysesstudies
willdisplayed;refertoFigure-7.
Figure-7.Listofstudies
•SelecttheStatic1studyfromthelist.1factorwillautomaticallyappearintheFactorcolumnadjacenttothestudyandonemorerowwillbeaddedbelowtheselectedfield.
•ClickontheemptyfieldunderStudycolumnandselecttheStatic2study
fromthedrop-downasdiscussedearlier.
•ClickontheOKbuttonfromthePropertyManager.
RunningtheDesignStudy• Click on theRun button in theRibbon. The combining process of twostudieswillstart.
•Afterthestudyiscomplete,theresultswillbedisplayedintheResultnodeoftheAnalysisManager;refertoFigure-8.
Figure-8.Resultsaftercombination
•Right-clickontheResultsnodeandselecttheDefineFactorofSafetyPlotbutton. TheFactor of Safety PropertyManager will be displayed; refer toFigure-9.
Figure-9.FactorofsafetyPropertyManager
•ClickontheOKbuttonfromthePropertyManager.Thefactorofsafetyplotwillbecreatedinthemodelingarea;refertoFigure-10.
Figure-10.Factorofsafetyplot
DESIGNSTUDYDesign Study is used to perform the optimization of the model. There are
variousparametersofanobjectthatdecidewhetherthemodelundertesting
willsustainorfailunderthegivencondition.Outofalltheparameters
ofamodel,thereareafewparametersofourconcernthatwewanttouse
forsatisfyingourobjective.InaDesignStudy,ourobjectivecanbe:
•Reducingthemassofthemodel.
•Decreasingthetotalmanufacturingcostofthemodel.
•Increasingthestrengthofthemodelandsoon.
To achieve these objective, we need to manipulate with dimensions,
materials,processandsoon.InSolidWorksSimulationDesignStudyisused
toperformanoptimizationorevaluatespecificscenariosofyourdesign.
You can plot the updated bodies and the calculated results for different
iterationsorscenariosbyselectingtheircolumnsontheResultsViewtab.
Youtackleavastnumberofproblemsusingadesignstudy.
Youcan:
• Define multiple variables using any simulation parameter, or driving
globalvariable.
•Definemultipleconstraintsusingsensors.
•Definemultiplegoalsusingsensors.
•Analyzemodelswithoutsimulationresults.Forexample,youcanminimize
themassofanassemblywiththevariables,densityandmodeldimensions,
andtheconstraint,volume.
•Evaluatedesignchoicesbydefiningaparameterthatsetsbodiestouse
differentmaterialsasavariable.
TheproceduretousetheDesignStudyisgivennext.
Before starting the design study, it is important to understand that the
designstudyisakindofmacrowhichperformsaspecifictypeofanalysis
with a varying values of a specific parameters. For example, we have
performedastaticanalysisonatubeunderaspecificpressureandwefind
thatitsfactorofsafetyis64.Then,wewillperformadesignstudyto
findoutthethicknessoftubewhichisoptimumi.e.factorofsafetyis
greater than 1 and thickness of tube is minimum possible. In the next
example,wehaveperformedsuchatestonthemodel.
StartingDesignStudy•Openthemodelonwhichyouhaveperformedtherelevantanalysis.Inthis
example,wehaveperformedastaticanalysisandwehavefoundtheresults
asgiveninFigure-11.
Figure-11.Factorofsafetyofexample
• From the above figure, you can find that the factor of safety of the
modelunderthegiventestis11.
•Ifwecheckthedimensionsthenthethicknessofthemodelis7mm;refertoFigure-12.
Figure-12.Thicknessoftube
• Now, click on the Simulation tab in theRibbon. The tools related toanalysiswilldisplay.
•ClickonthedownarrowbelowStudyAdvisorandselecttheNewStudytoolfrom the list of tools displayed. The Study PropertyManager will be
displayed.
• Click on theDesign Study button and click on theOK button from the
PropertyManager.
•TheDesignStudypanewillbedisplayed;refertoFigure-13.
Figure-13.Designstudypane
SettingoptionsforDesignStudy•ClickontheDesignStudyOptionsbuttonfromtheDesignStudypane;referto Figure-14. The Design Study Properties PropertyManager will be
displayed;refertoFigure-15.
Figure-14.DesignStudyOptionsbutton
Figure-15.DesignStudyPropertiesPropertyManager
•Selecttherequiredradiobuttonandsetthedesiredparameterslike;for
fastresults,clickontheFastresultsradiobutton.
Specifyingparametersthataretobechanged• Click on the down arrow under the Variables node. A list of variable
optionswillbedisplayed;refertoFigure-16.
Figure-16.Variablesdrop-down
• Click on the Add Parameter option from the drop-down list. The
Parameters dialog box will be displayed and you will be prompted to
selectadimensionthatistobevaried;refertoFigure-17.
Figure-17.Parametersdialogbox
•Clickonthedimensionofthemodelthatyouwanttomakevariable;refer
toFigure-18.TheselecteddimensionwillbeaddedundertheValuecolumnintheParametersdialogbox.
Figure-18.Dimensionselectedasvariable
•ClickinthefieldbelowNamecolumninthedialogboxandspecifythenameasThickness;refertoFigure-19.
Figure-19.Nameofparameter
•Ifyouwanttospecify,thenclickinthenamefieldofsecondrowand
followthesameprocedure.Youcanalsospecifyotherparametersinspite
ofdimensions.Todoso,clickonthedownarrownexttoModelDimensionin Category column and select the desired category. There are four
categories from which you can specify the variables:Model Dimension,GlobalVariable,Simulationdata,andMaterialdata.
•Afterspecifyingthevariables,clickontheOKbuttonfromthedialog
box. The variable will be added in theDesign Study pane and its rangewillbedisplayed;refertoFigure-20.
Figure-20.Designvariablewithrange
•Weknowthatthethicknessofourmodelis7mmwithFactorofSafetyas11. Now, we need to move below this thickness value to get the optimumthicknessofthetube.
•ChangethevalueofMin,Max,andStepasshowninFigure-21byusingthespinners.
Figure-21.Valuestobechanged
Specifyingrestrictionsforchanges• Click on the down arrow under theConstraints node in theDesign Studypane.Alistofoptionswillbedisplayed.
•ClickontheAddSensoroptionfromthelist.TheSensorPropertyManagerwillbedisplayed;refertoFigure-22.
Figure-22.SensorPropertyManager
•Clickonthedrop-downintheSensorTyperollout.Alistofoptionswillbedisplayed.
•SelecttheSimulationDataoptionfromthelist;refertoFigure-23.
Figure-23.SimulationDataoption
•Ondoingso,theoptionsrelatedtosimulationdatawillbedisplayedin
thePropertyManager.
•ClickontheResultsdrop-downintheDataQuantityrolloutandselecttheFactorofSafetyoption;refertoFigure-24.
Figure-24.Factorofsafetyoption
•ClickontheOKbuttonfromtheSensorPropertyManagertoaddtheFactorof Safety constraint. The constraint will be added in the Design Studypane;refertoFigure-25.
Figure-25.FactorofsafetyinDesignStudypane
•ClickonthedownarrownexttoislessthanfieldandselecttheIsgreaterthanoption;refertoFigure-26.
Figure-26.Optiontobeselected
SettingGoalforthestudy•ClickonthedownarrowundertheGoalsnode.Alistofoptionswillbedisplayed;refertoFigure-27.
Figure-27.Goalsdropdown
• Click on the Add Sensor option. The Sensor PropertyManager will be
displayedasdiscussedearlier;refertoFigure-28.
Figure-28.SensorPropertyManagerforgoals
•ClickontheOKbuttonfromthePropertyManagertosetthemasstobeminimized.TheMasswillbeaddedasgoalintheDesignStudypane;refertoFigure-29.
Figure-29.GoaladdedinDesignStudy
RunningtheStudyWehavespecifiedallthenecessaryparametersforthestudyandareready
fortheanalysis.
•ClickontheRunbuttonintheDesignStudypane,thedesignstudywillstart.
• After the study is solved, the results will be displayed as shown in
Figure-30.
Figure-30.Resultsofdesignstudy
• The green highlighted box displays the optimum result for the analysis
anditsrelatedparametersusedforoptimization.
Youcanspecifymorevariablesforchangingthedesignandtesttheresults
forpractice.
FundamentalsofFEA
Chapter14
TopicsCovered
Themajortopicscoveredinthischapterare:
•IntroductiontoFEA.
•GeneralDescriptionofFEA
•SolvingaproblemwithFEA
•FEAV/sClassicalMethods
•FEAV/sFiniteDifferentMethod
•NeedforStudyingFEM
•RefiningMesh
•HigherorderelementV/sRefinedMesh
•OptimumprocessofFEAthroughSolidWorksSimulation
INTRODUCTIONThe finite element analysis is a numerical technique. In this method all
thecomplexities of the problems, like varying shape, boundary conditions
and loads are maintained as they are but the solutions obtained are
approximate.Becauseofitsdiversityandflexibilityasananalysistool,
it is receiving much attention in engineering. The fast improvements in
computerhardwaretechnologyandslashingofcostofcomputershaveboosted
this method, since the computer is the basic need for the application of
thismethod.Anumberofpopularbrandoffiniteelementanalysispackages
arenowavailablecommercially.SomeofthepopularpackagesareSolidWorks
Simulation,NASTRAN,NISA,andANSYS.Usingthesepackagesonecananalyse
severalcomplexstructures.
The finite element analysis originated as a method of stress analysis in
the design of aircrafts. It started as an extension of matrix method of
structuralanalysis.Todaythismethodisusednotonlyfortheanalysisin
solid mechanics, but even in the analysis of fluid flow, heat
transfer,electricandmagneticfieldsandmanyothers.Civilengineersuse
this method extensively for the analysis of beams, space frames, plates,
shells, folded plates, foundations, rock mechanics problems and seepage
analysis of fluid through porous media. Both static and dynamic problems
canbehandledbyfiniteelementanalysis.Thismethodisusedextensively
for the analysis and design of ships, aircraft, space crafts, electric
motorsandheatengines.
GENERALDESCRIPTIONOFTHEMETHODInengineeringproblemstherearesomebasicunknowns.Iftheyarefound,
thebehavioroftheentirestructurecanbepredicted.Thebasicunknowns
or the Field variables which are encountered in the engineering problems
are displacements in solid mechanics, velocities in fluid mechanics,
electricandmagneticpotentialsinelectricalengineeringandtemperatures
inheatflowproblems.
Inacontinuum,theseunknownsareinfinite.Thefiniteelementprocedure
reduces such unknowns to a finite number by dividing the solution region
into small parts called elements and by expressing the unknown field
variables in terms of assumed approximating functions (Interpolating
functions/Shapefunctions)withineachelement.Theapproximatingfunctions
aredefinedintermsoffieldvariablesofspecifiedpointscallednodesor
nodal points. Thus in the finite element analysis, the unknowns are the
field variables of the nodal points. Once these are found the field
variablesatanypointcanbefoundbyusinginterpolationfunctions.
After selecting elements and nodal unknowns next step in finite element
analysisistoassembleelementpropertiesforeachelement.Forexample,
insolidmechanics,wehavetofindtheforce-displacementi.e.stiffness
characteristics of each individual element. Mathematically this
relationshipisoftheform
where[k]eiselementstiffnessmatrix,{δ}
eisnodaldisplacementvectorof
theelementand{F}eisnodalforcevector.Theelementofstiffnessmatrix
kij represent the force in coordinate direction ‘i’ due to a unit
displacement in coordinate direction ‘j’. Four methods are available for
formulating these element properties viz. direct approach, variational
approach, weighted residual approach and energy balance approach. Any one
of these methods can be used for assembling element properties. In solid
mechanics variational approach is commonly employed to assemble stiffness
matrixandnodalforcevector(consistentloads).
Element properties are used to assemble global properties/structure
properties to get system equations [k] {δ } = {F}. Then the boundary
conditions are imposed. The solution of these simultaneous equations give
the nodal unknowns. Using these nodal values additional calculations are
made to get the required values e.g. stresses, strains, moments, etc. in
solidmechanicsproblems.
Thusthevariousstepsinvolvedinthefiniteelementanalysisare:
(i)Selectsuitablefieldvariablesandtheelements.
(ii)Discritisethecontinua.
(iii)Selectinterpolationfunctions.
(iv)Findtheelementproperties.
(v)Assembleelementpropertiestogetglobalproperties.
(vi)Imposetheboundaryconditions.
(vii)Solvethesystemequationstogetthenodalunknowns.
(viii)Maketheadditionalcalculationstogettherequiredvalues.
ABRIEFEXPLANATIONOFFEAFORASTRESSANALYSISPROBLEM
Thestepsinvolvedinfiniteelementanalysisareclarifiedbytakingthe
stressanalysisofatensionstripwithfillets(referFigure-1).Inthis
problemstressconcentrationistobestudiesinthefilletzone.Sincethe
problemishavingsymmetryaboutbothxandyaxes,onlyonequarterofthe
tensionstripmaybeconsideredasshowninFigure-2.Aboutthesymmetric
axes, transverse displacements of all nodes are to be made zero. The
variousstepsinvolvedinthefiniteelementanalysisofthisproblemare
discussedbelow:
Step 1: Four noded isoparametric element is selected for the analysis
(However note that 8 noded isoparametric element is ideal for this
analysis). The four noded iso-parametric element can take quadrilateral
shapealsoasrequiredforelements12,15,18,etc.Asthereisnobending
ofstrip,onlydisplacementcontinuityistobeensuredbutnottheslope
continuity.Hencedisplacementsofnodesinxandydirectionsaretakenas
basicunknownsintheproblem.
Figure-1.TensionStripwithFillet
Figure-2.Descritizationofquateroftensionstrip
Step 2: The portion to be analysed is to be discretised. Figure-2 shows
discretised portion. For this 33 elements have been used. There are 48
nodes.Ateachnodeunknownsarexandycomponentsofdisplacements.Hence
inthisproblemtotalunknowns(displacements)tobedeterminedare48×2
=96.
Step3:Thedisplacementofanypointinsidetheelementisapproximatedby
suitablefunctionsintermsofthenodaldisplacementsoftheelement.For
thetypicalelement(Fig.1.3b),displacementsatPare
u=ΣNiui=N
1u1+N
2u2+N
3u3+N
4u4
andv=ΣNivi=N
1v1+N
2v2+N
3v3+N
4v4…(1.2)
TheapproximatingfunctionsNiarecalledshapefunctionsorinterpolation
functions.Usuallytheyarederivedusingpolynomials.
Step4:Nowthestiffnesscharactersandconsistentloadsaretobefound
foreachelement.Therearefournodesandateachnodedegreeoffreedom
is 2. Hence degree of freedom in each element is 4 × 2 = 8. The
relationship between the nodal displacements and nodal forces is called
elementstiffnesscharacteristics.Itisoftheform
[k]e{δ}
e={F}
e,asexplainedearlier.
Fortheelementunderconsideration,keis8×8matrixandδ
e and F
e are
vectors of 8 values. In solid mechanics element stiffness matrix is
assembledusingvariationalapproachi.e.byminimizingpotentialenergy.
Iftheloadisactinginthebodyofelementoronthesurfaceofelement,
itsequivalentatnodalpointsaretobefoundusingvariationalapproach,
sothatrighthandsideoftheaboveexpressionisassembled.Thisprocess
iscalledfindingconsistentloads.
Step5:Thestructureishaving48×2=96displacementandloadvector
componentstobedetermined.
Henceglobalstiffnessequationisoftheform
[k]{δ}={F}
96×9696×196×1
Each element stiffness matrix is to be placed in the global stiffness
matrix appropriately. This process is called assembling global stiffness
matrix.InthisproblemforcevectorFiszeroatallnodesexceptatnodes
45,46,47and48inxdirection.Forthegivenloadingnodalequivalent
forcesarefoundandtheforcevectorFisassembled.
Step6:Inthisproblem,duetosymmetrytransversedisplacementsalongAB
andBCarezero.Thesystemequation[k]{δ}={F}ismodifiedtoseethat
thesolutionfor{δ}comesoutwiththeabovevalues.Thismodificationof
systemequationiscalledimposingtheboundaryconditions.
Step7:Theabove96simultaneousequationsaresolvedusingthestandard
numerical procedures like Gausselimination or Choleski’s decomposition
techniquestogetthe96nodaldisplacements.
Step8:Nowtheinterestoftheanalystistostudythestressesatvarious
points. In solid mechanics the relationship between the displacements and
stressesarewellestablished.Thestressesatvariouspointsofinterest
maybefoundbyusingshapefunctionsandthenodaldisplacementsandthen
stressescalculated.Thestressconcentrationsmaybestudiesbycomparing
thevaluesobtainedatvariouspointsinthefilletzonewiththevaluesat
uniformzone,farawayfromthefillet(whichisequaltoP/b2t).
FINITEELEMENTMETHODV/SCLASSICALMETHODS
1.Inclassicalmethodsexactequationsareformedandexactsolutionsare
obtainedwhereasinfiniteelementanalysisexactequationsareformedbut
approximatesolutionsareobtained.
2. Solutions have been obtained for few standard cases by classical
methods, where as solutions can be obtained for all problems by finite
elementanalysis.
3. Whenever the following complexities are faced, classical method makes
thedrasticassumptions’andlooksforthesolutions:
(a)Shape
(b)Boundaryconditions
(c)Loading
Figure-3showssuchcasesintheanalysisofslabs(plates).
Togetthesolutionintheabovecases,rectangularshapes,sameboundary
conditionalongasideandregularequivalentloadsaretobeassumed.In
FEMnosuchassumptionsaremade.Theproblemistreatedasitis.
4. When material property is not isotropic, solutions for the problems
becomeverydifficultinclassicalmethod.Onlyfewsimplecaseshavebeen
tried successfully by researchers. FEM can handle structures with
anisotropicpropertiesalsowithoutanydifficulty.
5.Ifstructureconsistsofmorethanonematerial,itisdifficulttouse
classicalmethod,butfiniteelementcanbeusedwithoutanydifficulty.
6.Problemswithmaterialandgeometricnon-linearitiescannotbehandled
byclassicalmethods.
ThereisnodifficultyinFEM.
Figure-3.Analysisofslab
Hence FEM is superior to the classical methods only for the problems
involving a number of complexities which cannot be handled by classical
methodswithout making drastic assumptions. For all regular problems, the
solutionsbyclassicalmethodsarethebestsolutions.Infact,tocheckthe
validityoftheFEMprogramsdeveloped,theFEMsolutionsarecomparedwith
thesolutionsbyclassicalmethodsforstandardproblems.
FEMVSFINITEDIFFERENCEMETHOD(FDM)1. FDM makes pointwise approximation to the governing equations i.e. it
ensurescontinuityonlyatthenodepoints.Continuityalongthesidesof
grid lines are not ensured. FEM make piecewise approximation i.e. it
ensures the continuity at node points as well as along the sides of the
element.
2.FDMdonotgivethevaluesatanypointexceptatnodepoints.Itdonot
giveanyapproximatingfunctiontoevaluatethebasicvalues(deflections,
incaseofsolidmechanics)usingthenodalvalues.FEMcangivethevalues
atanypoint.Howeverthevaluesobtainedatpointsotherthannodesareby
usingsuitableinterpolationformulae.
3.FDMmakesstairtypeapproximationtoslopingandcurvedboundariesas
shown in Figure-4. FEM can consider the sloping boundaries exactly. If
curved elements are used, even the curved boundaries can be handled
exactly.
Figure-4.FDMapproximationofshape
4. FDM needs larger number of nodes to get good results while FEM needs
fewernodes.
5. With FDM fairly complicated problems can be handled where as FEM can
handleallcomplicatedproblems.
NEEDFORSTUDYINGFEMNow,anumberofusersfriendlypackagesareavailableinthemarket.Hence
onemayaskthequestion‘WhatistheneedtostudyFEA?’.
Theaboveargumentisnotsound.Thefiniteelementknowledgemakesagood
engineer better while just user without the knowledge of FEA may produce
more dangerous results. To use the FEA packages properly, the user must
knowthefollowingpointsclearly:
1.Whichelementsaretobeusedforsolvingtheprobleminhand.
2.Howtodiscritisetogetgoodresults.
3.Howtointroduceboundaryconditionsproperly.
4.Howtheelementpropertiesaredevelopedandwhataretheirlimitations.
5.Howthedisplaysaredevelopedinpreandpostprocessortounderstand
theirlimitations.
6. To understand the difficulties involved in the development of FEA
programs and hence the need for checking the commercially available
packageswiththeresultsofstandardcases.
UnlessuserhasthebackgroundofFEA,hemayproduceworstresultsandmay
gowithoverconfidence.HenceitisnecessarythattheusersofFEApackage
shouldhavesoundknowledgeofFEA.
WarningToFeaPackageUsersWhenhandcalculationsaremade,thedesigneralwaysgetsthefeelofthe
structureandgetroughideaabouttheexpectedresults.Thisaspectcannot
beignoredbyanydesigner,whateverbethereliabilityoftheprogram,a
complexproblemmaybesimplifiedwithdrasticassumptionsandFEAresults
obtained. Check whether expected trend of the result is obtained. Then
avoid drastic assumptions and get more refined results with FEA package.
User must remember that structural behaviour is not dictated by the
computerprograms.Hencethedesignershoulddevelopfeelofthestructure
andmakeuseoftheprogramstogetnumericalresultswhicharecloseto
structuralbehaviour.
One of the main concern for using FEA applications is selection of
elements, in other words discretization. The process of modeling a
structureusingsuitablenumber,shapeandsizeoftheelementsiscalled
discretization. The modeling should be good enough to get the results as
closetoactualbehaviorofthestructureaspossible.
Inastructurewecomeacrossthefollowingtypesofdiscontinuities:
(a)Geometric
(b)Load
(c)Boundaryconditions
(d)Material.
GeometricDiscontinuitiesWherever there is sudden change in shape and size of the structure there
shouldbeanodeorlineofnodes.Figure-5showssomeofsuchsituations.
Figure-5.GeometricDiscontinuityinthepart
DiscontinuityofLoadsConcentrated loads and sudden change in the intensity of uniformly
distributed loads are the sources of discontinuity of loads. A node or a
line of nodes should be there to model the structure. Some of these
situationsareshowninFigure-6.
Figure-6.FEMModelandslabwithdifferentUDL
DiscontinuityofBoundaryconditionsIf the boundary condition for a structure suddenly change we have to
discretize such that there is node or a line of nodes. This type of
situationsareshowninFigure-7.
Figure-7.Slabwithintermediatewallandcolumns
MaterialDiscontinuityNodeornodelinesshouldappearattheplaceswherematerialdiscontinuity
isseen;refertoFigure-8.
Figure-8.MaterialDiscontinuity
REFININGMESHTo get better results the finite element mesh should be refined in the
followingsituations:
(a)Toapproximatecurvedboundaryofthestructure
(b)Attheplacesofhighstressgradients.
SuchasituationisshowninFigure-9.
Figure-9.Refinedmeshnearcurvedboundary
UseOfSymmetryWhereverthereissymmetryintheproblem,itshouldbemadeuse.Bydoing
so,lotofmemoryrequirementisreducedorinotherwordswecanusemore
elements (refined mesh) for the same capacity of computer memory. When
symmetryistobeused,itistobenotedthatatrightanglestotheline
ofsymmetrydisplacementiszero.
HIGHERORDERELEMENTSV/SREFINEDMESH
Accuracy of calculation increases if higher order elements are used.
Accuracycanalsobeincreasedbyusingmorenumberofelements.Limitation
onuseofnumberofelementscomesfromthetotaldegreesoffreedomthe
computercanhandle.Thelimitationmaybeduetocostofcomputationtime
also.Hencetousehigherorderelementswehavetouselessnumberofsuch
elements. The question arises whether to use less number of higher order
elementsormorenumberoflowerorderelementsforthesametotaldegree
of freedom. There are some studies in this matter keeping degree of
accuracy per unit cost as the selection criteria. However the cost of
calculation is coming down so much that such studies are not relevant
today.Accuracyaloneshouldbeselectioncriteriawhichmaybecarriedout
initially on the simplified problem and based on it element may be
selectionfordetailedstudy.
OPTIMUMPROCESSOFFEATHROUGHSOLIDWORKSSIMULATION
With the knowledge of the basics discussed above we can summarize the
processofperforminganalysisasfollows:
1. Construct the part(s) in a solid modeler. It is surprisingly easy to
accidentally build flawed models with tiny lines, tiny surfaces or tiny
interiorvoids.Thepartwilllookfine,exceptwithextremezooms,butit
may fail to mesh. Most systems have checking routines that can find and
repairsuchproblemsbeforeyoumoveontoanFEAstudy.Sometimesyoumay
have to export a part, and then import it back with a new name because
imported parts are usually subjected to more time consuming checks than
“native”parts.Whenmultiplepartsformanassembly,alwaysmeshandstudy
the individual parts before studying the assembly. Try to plan ahead and
introduce split lines into the part to aid in mating assemblies and to
locateloadregionsandrestraint(orfixtureorsupport)regions.Today,
constructionofapartisprobablythemostreliablestageofanystudy.
2.Defeaturethesolidpartmodelformeshing.Thesolidpartmaycontain
features, like a raised logo, that are not necessary to manufacture the
part,orrequiredforanaccurateanalysisstudy.Theycanbeomittedfrom
the solid used in the analysis study. That is a relative easy operation
supportedbymostsolidmodelers(suchasthe“suppress”optioninSW)to
help make smaller and faster meshes. However, it has the potential for
introducingserious,ifnotfatal,errorsinafollowingengineeringstudy.
This is a reliable modeling process, but its application requires
engineering judgment. For example, removing small radius interior fillets
can greatly reduces the number of elements and simplifies the mesh
generation.But,thatcreatessharpreentrantcornersthatcanyieldfalse
infinitestresses.
Those false high stress regions may cause you to overlook other areas of
truehighstresslevels.Smallholesleadtomanysmallelements(andlong
run times). They also cause stress concentrations that raise the local
stresslevelsbyafactorofthreeormore.Thedecisiontodefeaturethem
dependsonwheretheyarelocatedinthepart.Iftheylieinahighstress
regionyoumustkeepthem.Butdefeaturingthemisallowedifyouknowthey
occurinalowstressregion.Suchdecisionsarecomplicatedbecausemost
partshavemultiplepossibleloadingconditionsandalowstressregionfor
oneloadcasemaybecomeahighstressregionforanotherloadcase.
3.Combinemultiplepartsintoanassembly.Again,thisiswellautomated
and reliable from the geometric point of view and assemblies “look” as
expected. However, geometric mating of part interfaces is very different
for defining their physical (displacement, or temprature) mating. The
physicalmatingchoicesareoftenunclearandtheengineermayhavetomake
a range of assumptions, study each, and determine the worst case result.
Havingtousephysicalcontactsmakesthelinearproblemrequireiterative
solutionsthattakealongtimetorunandmightfailtoconverge.
4. Select the element type. Some FEA systems have a huge number of
available element types (with underlying theoretical restrictions). The
SolidWorkssystemhasonlythefundamentaltypesofelements.Namely,truss
elements (bars), frame elements (beams), thin shells (or flat plates),
thickshells,andsolids.TheSWsimulationsystemselectstheelementtype
(beginningin2009)basedontheshapeofthepart.Theuserisallowedto
covert a non-solid element region to a solid element region, and visa
versa.Knowingwhichclassofelementwillgiveamoreaccurateorfaster
solution requires training in finite element theory. At times a second
elementtypestudyisusedtohelpvalidateastudybasedonadifferent
elementtype.
5.Meshthepart(s)orassembly,rememberingthatthemeshsolidmaynotbe
thesameasthepartsolid.AgeneralruleinanFEAisthatyourcomputer
never has enough speed or memory. Sooner or later you will find a study
thatyoucannotexecute.Oftenthatmeansyoumustutilizeacrudemesh(or
at least crude in some region) and/or invoke the use of symmetry or
antisymmetryconditions.Localsolutionerrorsinastudyareproportional
totheproductofthelocalelementsizeandthegradientofthesecondary
variables(i.e.,gradientofstressorheatflux).Therefore,youexercise
mesh control to place small elements where your engineering judgment
estimateshighstress(orflux)regions,aswellaslargeelementsinlow
stressregions.
The local solution error also depends on the relative sizes of adjacent
elements. You do not want skinny elements adjacent to big ones. Thus,
automatic mesh generators have options to gradually vary adjacent element
sizesfromsmallesttobiggest.
Thesolidmodelsenttothemeshgeneratorfrequentlyshouldhaveloador
restraint(fixture)regionsformedbysplitlines,evenifsuchsplitsare
not needed for manufacturing the parts. The mesh typically should have
refinementsatsourceorloadregionsandsupportregions.
Ameshmustlooklikethepart,butthatisnotsufficientforacorrect
study. A single layer of elements filling a part region is almost never
enough.Iftheregioniscurved,orsubjectedtobending,youwantatleast
three layers of quadratic elements, but five is a desirable lower limit.
Forlinearelementsyouatleastdoublethosenumbers.
Most engineers do not have access to the source code of their automatic
mesh generator. When the mesher fails you frequently do not know why it
failedorwhattodoaboutit.Oftenyouhavetore-trythemeshgeneration
with very large element sizes in hopes of getting some mesh results that
cangivehintsastowhyotherattemptsfailed.Themeshingofassemblies
often fails. Usually the mesher runs out of memory because one or more
partshadaverysmall,oftenunseen,featurethatcausesahugenumberof
tiny elements to be created. You should always attempt to mesh each
individualparttospotsuchproblemsbeforeyouattempttomeshthemasa
memberofanassembly.
Automatic meshing, with mesh controls, is usually simple and fast today.
However,itisonlyasreliableasthemodifiedpartorassemblysupplied
to it. Distorted elements usually do not develop in automatic mesh
generators, due to empirical rules for avoiding them. However, distorted
elements locations can usually be plotted. If they are in regions of low
gradientsyoucanusuallyacceptthem.
You should also note that studies involving natural frequencies are
influencedmostbythedistributionofthemassofthepart.Thus,theycan
still give accurate results with meshes that are much cruder than those
thatwouldbeacceptableforstressorthermalstudies.
6. Assign a linear material to each part. Modern FEA systems have a
materiallibrarycontainingthe“linear”mechanical,thermal,and/orfluid
properties of most standardized materials. They also allow the user to
define custom properties. The property values in such tables are often
misinterpretedtobemoreaccurateandreliablethantheyactuallyare.The
reportedpropertyvaluesareacceptedaveragevaluestakenfrommanytests.
Rarelyarethereanydataaboutthedistributionoftestresults,orwhat
standarddeviationwasassociatedwiththetests.Mosttestsyieldresults
thatfollowa“bellshaped”curvedistribution,orasimilarskewedcurve.
Whenyouacceptatabulatedpropertyvalueasasinglenumbertobeusedin
the FEA calculation remember it actually has a probability distribution
associatedwithit.Youneedtoassignacontributiontothetotalfactor
ofsafetytoallowforvariationsfromthetabulatedpropertyvalue.
Thevaluesofpropertiesfoundinamaterialtablecanappearmoreorless
accuratedependingontheunitsselected.Thatisanillusionoftencaused
byconvertingonesetofunitstoanother,butnottruncatingtheresultto
thesamenumberofsignificantfiguresavailableintheactualtestunits.
For example, the elastic modulus of one steel is tabulated from the
original test as 210 MPa, but when displayed in other units it shows as
30,457,924.92psi.Whichonedoyoubelievetobetheexperimentalaccurate
value;the3digitvalueorthe10digitone?Theansweraffectshowyou
shouldviewandreportstressresults.Theaxialstressinabarisequal
totheelasticmodulustimesthestrain, .Thus,ifEis
only known to three or four significant figures then the reported stress
resultshouldhavenomoresignificantfigures.Materialdataareusually
morereliablethantheloadingvalues(considered
next),butlessaccuratethatthemodelormeshgeometries.
7.Selectregionsofthepart(s)tobeloadedandassignloadlevelsand
load types to each region. In mathematical terminology, load or flux
conditionsonaboundaryregionarecalledNeumannboundaryconditions,or
nonessential conditions. The geometric regions can be points (in theory),
lines,surfaces,orvolumes.Iftheyarenotexistingfeaturesofthepart,
then you should apply split lines to the part to create them before
activatingthemeshgenerator.Pointforces,orheatsources,arecommonin
undergraduatestudies,butinanFEAtheycausefalseinfinitestresses,or
heatflux.Ifyouincludethemdonotbemisleadbythehighlocalvalues.
Refining the mesh does not help since the smallest element still reports
nearinfinitevalues.
Inreality,pointloadsarebettermodeledasatotalforce,orpressure,
acting over a small area formed by prior split lines. Saint Venant’s
Principle states that two different, but statically equivalent, force
systemsactingonasmallportionofthesurfaceofabodyproducethesame
stress distributions at distance large in comparison with the linear
dimensions of the portion where the forces act. That also implies that
concentratedsourcesquicklybecomere-distributed.
Inundergraduatestaticsanddynamicscoursesengineersaretaughttothink
in terms of point forces and couples. Solid elements do not accept pure
couples as loads, but statically equivalent pressures can be applied to
solids and yield the correct stresses. Indeed, a couple at a point is
almostimpossibletocreate,sothedistributionofpressuresisprobably
morelikethetruesituation.
The magnitudes of applied loads are often guesses, or specified by a
governing design standard. For example, consider a wind load. A building
standardmayquoteapressuretobeappliedforagivenwindspeed.But,
howwelldoyouknowthewindspeedthatmightactuallybeexertedonthe
structure? Again, there probably is some type of “bell curve” around the
expected average speed. You need to assign a contribution to the total
factor of safety to allow for variations in the uncertainty of the load
valueoractualspatialdistributionofappliedloads.
Loading data are usually less accurate than the material data, but much
moreaccuratethattherestraintorsupportingconditionsconsiderednext.
8. Determine (or more likely assume) how the model interacts with the
surroundingsnotincludedinyourmodel.Thesearetherestraint(support,
or fixture) regions. In mathematical terminology, these are called the
essentialboundaryconditions,orDirichletboundaryconditions.Youcannot
afford to model everything interacting with a part. For many decades
engineers have developed simplified concepts to approximate surroundings
adjacent to a model to simplify hand calculations. They include roller
supports,smoothpins,cantilevered(encastre,orfixed)supports,straight
cable attachments, etc. Those concepts are often carried over to FEA
approachesandcanoversimplifythetruesupportnatureandleadtovery
largeerrorsintheresults.
Thechoiceofrestraints(fixations,supports)foramodelissurprisingly
difficult and is often the least reliable decision made by the engineer.
Smallchangesinthesupportscancauselargechangesintheresults.Itis
wise to try to investigate a number of likely or possible support
conditionsindifferentstudies.Whenindoubt,trytoincludemoreofthe
surroundingsupportmaterialandapplyassumedsupportconditionstothose
portionsatagreaterdistancefromcriticalpartfeatures.
Youneedtoassignacontributiontothetotalfactorofsafetytoallow
for variations in the uncertainty of how or where the actual support
conditionsoccur.Thatisespeciallytrueforbucklingstudies.
9. Solve the linear system of equations, or the eigenvalue problem. With
today’s numerical algorithms the solution of the algebraic system or
eigensystem is usually quite reliable. It is possible to cause ill-
conditionedsystems(largeconditionnumber)withmesheshavingbadaspect
ratios,orlargeelementsadjacenttosmallones,butthatisunlikelyto
happenwithautomaticmeshgenerators.
10.Checktheresults.Arethereactionsatthesupportsequalandopposite
to the sources you thought that you applied? Are the results consistent
withtheassumedlinearbehavior?Theengineeringdefinitionofaproblem
withlargedisplacementsisonewherethemaximumdisplacementismorethan
halfthesmallestgeometricthicknessofthepart.Theinternaldefinition
is a displacement field that significantly changes the volume of an
element.
That implies the element geometric shape noticeably changed from the
startingshape,andthattheshapeneedstobeupdatedinaseriesofmuch
smaller shape changes. Are the displacements big enough to require
resolutionwithlargedisplacementiterationsturnedon?Haveyouvalidated
the results with an analytic approximation, or different type of finite
element?Engineeringjudgmentsarerequired.
11. Post-process the solution for secondary variables. For structural
studies you generally wish to document the deflections, reactions and
stresses. For thermal studies you display the temperatures, heat flux
vectorsandreactionheatflows.Withnaturalfrequencymodelsyoushow(or
animate) a few mode shapes. In graphical displays, you can control the
numberofcontoursemployed,aswellastheirmaximumandminimumranges.
The latter is important if you want to compare two designs on a single
page. Limit the number of digits shown on the contour scale to be
consistentwiththematerialmodulus(orconductivity,etc.).Colorcontour
plotsoftendonotreproducewell,butgraphsdo,solearntousethemin
youdocumentation.
12. Determine (or more likely assume) what failure criterion applies to
yourstudy.Thisstageinvolvesassumptionsabouthowastructuralmaterial
mightfail.Thereareanumberoftheories.Mostarebasedonstressvalues
or distortional energy levels, but a few depend on strain values. If you
know that one has been accepted for your selected material then use that
one (as a contribution to the overall factor of safety). Otherwise, you
shouldevaluatemorethanonetheoryandseewhichistheworstcase.Also
keepinmindthatloadingorsupportuncertaintiescanleadtoarangeof
stress levels, and variations in material properties affect the strength
andunexpectedfailurescanoccurifthosetypesofdistributionshappento
intersectasinthenextfigure.
14. Optionally, post-process the secondary variables to measure the
theoreticalerrorinthestudy,andadaptivelycorrectthesolution.This
convergestoanaccuratesolutiontotheprobleminput,butperhapsnotto
theproblemtobesolved.Accurategarbageisstillgarbage.
15.Document,report,andfilethestudy.Thepartshape,mesh,andresults
shouldbereportedinimageform.Assumptionsonwhichthestudywasbased
shouldbeclearlystated,andhopefullyconfirmed.Thedocumentationshould
containan independent validation calculation, or two, from an analytical
approximationoranFEAbasedonatotallydifferentelementtype.
ProjectonAnalysis
Chapter15
TopicsCovered
Themajortopicscoveredinthischapterare:
•Project
•StaticAnalysis
•FrequencyAnalysis
•FatigueTest
PROJECT
In this project,we have a real-time problem of forging die. For your
understanding, I want to tell you that there are many components like
gears, shafts, rings, engine covers that are made with the help of a
forging machine. In a forging machine, a workpiece pre-heated at
temperatureofplasticdeformationisplacedinthebottomdieandtopdie
strikes to the workpiece. After this impact of 50kN to 1600kN on the
workpiece,theworkpiecetakestheshapeoftopandbottomdies;referto
Figure-1.
Figure-1.ForgingProcess
Now,wehavethebottomdiethatneedtobeanalyzedat115°Cofsurfacetemperatureandforceexertedonitssurfaceis200kN;refertoFigure-2andFigure-3.WeneedtofindouttheFactorofsafetyofthemodel.Ifit
is higher then methods to reduce the cost of model. If the FoS is lower
thenthemethodstoincreaseitforincreasingstrengthofthemodel.Also,
we need to check the model for Fatigue under the cycle of 100,000
loading/unloading. After performing the analysis, we will create a more
refinedmeshandthenwewillchecktheresultsagain.
Figure-2.Facesunderspecifiedtemperature
Figure-3.Facesundertheload
STARTINGSIMULATION•OpenthefileofdiemodelinSolidWorks(Thefileisavailableinthe
Resourcekit).
•ClickontheSimulationbuttonfromtheSOLIDWORKSAdd-InstabintheRibbon.TheSimulationtabwillbeaddedintheRibbon.
• Click on the Simulation tab. The tools related to simulation will be
displayed.
PERFORMINGTHESTATICANALYSIS• Click on the down arrow below Study Advisor in the Simulation tab’s
Ribbon.
•SelecttheNewStudybuttonfromthelistoftoolsdisplayed.TheStudyPropertyManagerwillbedisplayed.
•ClickontheStaticbuttonfromthePropertyManagerandclickontheOKbuttonfromthePropertyManager.
•ClickontheApplyMaterialbuttonfromtheRibbon.TheMaterial dialogboxwillbedisplayedasshowninFigure-4.
Figure-4.Materialdialogbox
•Bydefault,theAlloySteelmaterialisselectedfromthelistintheleftofthedialogbox.Ifnotselectedthenselectit.
•ClickontheApplybuttonandthentheClosebuttonfromthedialogbox.
•ClickonthedownarrowbelowFixtureAdvisor button in theRibbon andselecttheFixedGeometrybuttonfromthelist.
•TheFixturePropertyManagerwillbedisplayed.•Selectthebottomfaceofthemodeltofixit;refertoFigure-5.
Figure-5.Facetobefixed
•ClickontheOKbuttonfromthePropertyManager.
• Click on the down arrow below External Loads Advisor button in the
Ribbon.Thelistoftoolswillbedisplayed.
• Click on the Temperature button from the list. The TemperaturePropertyManagerwillbedisplayed.
•ClickontheSelectallexposedfacesbuttonfromthePropertyManager.Allthefaceswillgetselected.
•PressandholdtheCTRLkeyandselectthebottom,sideandtopfaceofthedie;refertoFigure-6.Thefaceswillgetdeselected.
Figure-6.Facesselectedfortemperature
•ClickontheTemperaturedrop-downintheTemperaturerolloutandselecttheCelsius(°C)option.
•ClickintheTemperatureeditboxandspecifythevalueas115.
•ClickontheOKbuttonfromthePropertyManager.
•Again,clickonthedownarrowbelowExternalLoadsAdvisorbuttonintheRibbon.
•Select theForce button from the list of tools. TheForce PropertyManager will bedisplayed.
•Selectthefacesvisiblefromthetopofthemodel;refertoFigure-7.
Figure-7.Facesforapplyingforce
•ClickintheForceValueeditboxandspecifythevalueas200000N.
•SelecttheTotalradiobuttonfromthePropertyManagerandclickontheOKbutton.
•ClickontheRunbuttonfromtheRibbon.Aftertheanalysisissolvedtheresultwillbedisplayed;refertoFigure-8.
Figure-8.Resultofstaticanalysis
•Right-clickontheResultsnodeinAnalysisManagerandselecttheDefineFactorOfSafetyPlotoptionfromtheshortcutmenudisplayed.
•TheFactorofSafetyPropertyManagerwillbedisplayed;refertoFigure-9.
Figure-9.FactorofSafetyPropertyManager
• Click on theOK button from thePropertyManager. TheFactor of Safetyplotwillbedisplayed;refertoFigure-10.
Figure-10.FactorofSafetyplot
PERFORMINGTHEFREQUENCYANALYSIS• Click on the down arrow below Study Advisor and select theNew Studybuttonfromthelistdisplayed.
•ClickontheFrequencybuttonfromtheStudyPropertyManagerandclickon the OK button from the PropertyManager. The tools related to
frequencyanalysiswillbedisplayed.
•ClickontheApplyMaterialbuttonfromtheRibbon.TheMaterialdialogboxwilldisplay.
•SelecttheAlloySteelfromtheleftofthedialogbox.
•ClickontheApplybuttonandthenontheClosebuttonfromthedialogbox.
•Fixthebottomfaceofthedieasdoneinthepreviousanalysisbyusing
theFixedGeometrybutton.
•ClickontheRunbuttonfromtheRibbontoperformtheanalysis.•Aftertheanalysisiscomplete,thenaturalfrequenciesofthemodelwill
bedisplayed;refertoFigure-11.
Figure-11.Resultoffrequencyanalysis
• Make sure that the frequency of the machine vibration is not matching
withthenaturalfrequenciesofthemodel.
PERFORMINGFATIGUESTUDY•ClickonthedownarrowbelowStudyAdvisorintheRibbon.Listofthetoolswillbedisplayed.
• Click on the New Study tool. The Study PropertyManager will be
displayed.
• Click on theFatigue button from thePropertyManager and click on theOKbuttonfromthePropertyManager.ThetoolsrelatedtoFatigueanalysiswillbedisplayed.
•Right-clickonLoading(-ConstantAmplitude-)intheAnalysisManagerandselecttheAddEventoption;refertoFigure-12.TheAddEvent(Constant)PropertyManagerwillbedisplayed;refertoFigure-13.
Figure-12.AddEventoption
Figure-13.AddEventPropertyManager
•ClickintheCycleseditboxandspecifythevalueas100,000.
• Click on the Loading Type drop-down and select the Zero Based (LR=0)optionfromthedrop-downlist.
•ClickontheOKbuttonfromthePropertyManagertoaddtheevent.NotethatnameofpartwillbeaddedasanewnodeintheAnalysisManager.
•Right-clickonthenameofthepartandselecttheApply/EditFatigueDataoption;refertoFigure-14.TheMaterialdialogboxwillbedisplayedwiththeFatigueSNCurvestabactivated;refertoFigure-15.
Figure-14.Applyingfatiguedata
Figure-15.Materialdialogboxwithfatigueoptions
• Click on theDerive from material Elastic Modulus radio button and thenclick on the Based in ASME Carbon Steel curves radio button. (Due to
selectionoftheseradiobuttons,theSNcurveofacarbonsteelwillbe
usedwhichisderivedfromitselasticitycurve.)
• Click on theApply button and then click on theClose button from thedialogbox.Now,wearereadytoperformtheanalysis.
•ClickontheRunbuttonfromtheRibbon.Theanalyzingwillstart.•TheresultsoftheanalysiswillbeaddedintheResultsnode.
• Expand the node and double-click on the results to display the plot;
refertoFigure-16.
Figure-16.Fatigueresult
•Right-clickontheResultsnodeandselecttheDefineFatiguePlotoption;refer to Figure-17. The Fatigue Plot PropertyManager will be displayed;refertoFigure-18.
Figure-17.Definefatigueplotoption
Figure-18.FatiguePlotPropertyManager
•ClickontheLoadFactorradiobuttonandclickontheOKbuttonfromthe
PropertyManager. The load factor plot (in other words,Factor of Safetyforfatigue)willbedisplayed;refertoFigure-19.
Figure-19.Factorofsafetyfatigue
•Fromthescale,theyoucanfindthattheminimumfactorofsafetyofthe
fatiguestudyis3.6.
SinceourFactorofSafetyfortheproblemisoptimum,sowedonotrequiredtoperformtheDesignStudyasperformedinpreviouschapters.Although,youcanperformtheDesignStudytofindabetterproduct.
Now,Ihavealittleworkforyou:
GobacktoStaticStudyanalysisbyclickingontheStatic1tabatthebottombar of the modeling area. Note that the Factor of Safety is 2.1 for thisanalysis.Now,Right-clickontheMeshnodeintheAnalysisManager;refertoFigure-20.
Figure-20.ShortcutmenuforMesh
SelecttheCreateMeshbutton,makethemeshingextremelyfineandthenre-runthestaticanalysis.Now,checktheFactorofSafetyofthemodel.Isitthesameordifferent.
Ifdifferentthenwhy?Askyourtutor.
For online training on SolidWorks, SolidWorks Simulation and SolidWorks
Electrical, please write us at cadcamcaeworks@gmail.com or
info@cadcamcaeworks.com
TherearemanypointswhereyouwillneedthemodelingtoolsofSolidWorks
likewhencreatingsurfacesforsimplification.SolidWorks2017BlackBookfromthesameauthorcanbenefitinmodelingtools.Ifyouwanttolearn
theSolidWorksmodelingtoolsthenpleasehavelookonthebook.
PracticeQuestions
TopicsCovered
Themajortopicscoveredinthischapterare:
•Project
•StaticAnalysis
•FrequencyAnalysis
•FatigueTest
PROBLEM1
Sometimesweseepeoplefightingandinsomeextremecases,fightingwith
thehelpofBaseballbats.Wearenotheretodiscussconceptsoffighting
butoncethefightingisover,everybodyisbusytoseeeffectofbaseball
batonhumans.Duetounknownelasticpropertyofhumanbody,wecannot
performanalysistofindeffectofbaseballbatonhumans,butherewecan
checktheeffectofforceexertedonthebaseballbatduetosomefreaks;
refertoFigure-1.
Figure-1.Problem1
Weassumeittobeastaticanalysis.Checkwhetherthebatwillbreakor
not.
PROBLEM2
Thewallofahouseis7mwide,6mhighand0.3mthickmadeupofbrick.
The thermal conductivity of brick is k = 0.6 W/m.K. If the inside
temperatureofwallis16 oCandoutsidetemperatureis6 oCthenfindout
theheatlostfrominsidewalltooutsidewallinasteadystatecondition.
ThemodelisgiveninFigure-2.
Figure-2.Problem2
Note that to perform this thermal analysis, you need to create a new
materialwiththermalpropertiesasfollow:
ThermalConductivity=0.6W/(m.K)
Specificheat=1214J/(kg.K)
Massdensity=2405kg/m3
PROBLEM3
Anaxialpullof35kNisappliedattheendsofashaftasshowninFigure-3. If the material is Alloy Steel then find the total elongation in theshaft.
Figure-3.Problem3shaft
PROBLEM4
Acastironlinkisrequiredtotransmitasteadytensileloadof45kN.The
initialboundaryconditionsaregiveninFigure-4.
Figure-4.Problemoflink
Findouttheoptimumthicknessoflinksothatfactorofsafetyis3.
PROBLEM5
A part of car jack assembly is displayed in Figure-5 with its boundary
conditions.Optimizetheassemblywithrespecttomaterialcost.Notethat
allthecontactsarenopenetrationasyoufindinarealcarjack.
Figure-5.Problem5
PROBLEM6
AnassemblyofcoolingfinsandCPUisdisplayedinFigure-6withboundary
conditions.Thebulktemperatureis300Kandoperatingtemperaturebandfor
CPUis304Kto354K.Checkiffinsareenoughtodissipatetheheat.If
notthenperformmodificationsinfintodissipateheat.Notethatfinsand
heatsinkareperfectlybondedforheattransfer.
Figure-6.Problem6
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